diff --git a/src/OpenRiaServices.Client/Framework/DomainClient.cs b/src/OpenRiaServices.Client/Framework/DomainClient.cs
index 28c66be69..7b6b8eeff 100644
--- a/src/OpenRiaServices.Client/Framework/DomainClient.cs
+++ b/src/OpenRiaServices.Client/Framework/DomainClient.cs
@@ -15,7 +15,7 @@ namespace OpenRiaServices.Client
     /// </summary>
     public abstract class DomainClient
     {
-        private ReadOnlyCollection<Type> _entityTypes;
+        private Type[] _entityTypes;
 
         /// <summary>
         /// Gets or sets the collection of Entity Types this <see cref="DomainClient"/> will operate on.
@@ -32,7 +32,7 @@ public IEnumerable<Type> EntityTypes
                 {
                     throw new InvalidOperationException(OpenRiaServices.Client.Resource.DomainClient_EntityTypesAlreadyInitialized);
                 }
-                this._entityTypes = new ReadOnlyCollection<Type>(value.ToList());
+                this._entityTypes = value.ToArray();
             }
         }
 
diff --git a/src/OpenRiaServices.Client/Framework/Entity.cs b/src/OpenRiaServices.Client/Framework/Entity.cs
index 8757f4f3a..5ade6b54a 100644
--- a/src/OpenRiaServices.Client/Framework/Entity.cs
+++ b/src/OpenRiaServices.Client/Framework/Entity.cs
@@ -1610,20 +1610,8 @@ protected internal bool CanInvokeAction(string name)
         /// </remarks>
         /// <returns>Collection of custom method invocations pending for this entity</returns>
         [Display(AutoGenerateField = false)]
-        public IEnumerable<EntityAction> EntityActions
-        {
-            get
-            {
-                if (this._customMethodInvocations != null)
-                {
-                    return new ReadOnlyCollection<EntityAction>(this._customMethodInvocations);
-                }
-                else
-                {
-                    return Enumerable.Empty<EntityAction>();
-                }
-            }
-        }
+        public IReadOnlyCollection<EntityAction> EntityActions
+            => this._customMethodInvocations != null ? this._customMethodInvocations : Array.Empty<EntityAction>();
 
         /// <summary>
         /// Return the entity identity, suitable for hashing. If the entity
diff --git a/src/OpenRiaServices.Client/Framework/EntityChangeSet.cs b/src/OpenRiaServices.Client/Framework/EntityChangeSet.cs
index 0b1aef4fc..6a96ae10d 100644
--- a/src/OpenRiaServices.Client/Framework/EntityChangeSet.cs
+++ b/src/OpenRiaServices.Client/Framework/EntityChangeSet.cs
@@ -14,7 +14,7 @@ public sealed class EntityChangeSet : IEnumerable<Entity>
         private ReadOnlyCollection<Entity> _addedEntities;
         private ReadOnlyCollection<Entity> _removedEntities;
         private ReadOnlyCollection<Entity> _modifiedEntities;
-        private IEnumerable<ChangeSetEntry> _changeSetEntries;
+        private List<ChangeSetEntry> _changeSetEntries;
 
         internal EntityChangeSet(
             ReadOnlyCollection<Entity> addedEntities,
@@ -42,7 +42,7 @@ internal EntityChangeSet(
         /// <summary>
         /// Gets the collection of added Entities
         /// </summary>
-        public ReadOnlyCollection<Entity> AddedEntities
+        public IReadOnlyList<Entity> AddedEntities
         {
             get
             {
@@ -50,7 +50,7 @@ public ReadOnlyCollection<Entity> AddedEntities
             }
             internal set
             {
-                this._addedEntities = value;
+                this._addedEntities = value is ReadOnlyCollection<Entity> list  ? list : new ReadOnlyCollection<Entity>(value.ToArray());
             }
         }
 
@@ -70,7 +70,7 @@ public bool IsEmpty
         /// <summary>
         /// Gets the collection of modified entities
         /// </summary>
-        public ReadOnlyCollection<Entity> ModifiedEntities
+        public IReadOnlyList<Entity> ModifiedEntities
         {
             get
             {
@@ -78,14 +78,14 @@ public ReadOnlyCollection<Entity> ModifiedEntities
             }
             internal set
             {
-                this._modifiedEntities = value;
+                this._modifiedEntities = value is ReadOnlyCollection<Entity> list ? list : new ReadOnlyCollection<Entity>(value.ToArray());
             }
         }
 
         /// <summary>
         /// Gets the collection of removed entities
         /// </summary>
-        public ReadOnlyCollection<Entity> RemovedEntities
+        public IReadOnlyList<Entity> RemovedEntities
         {
             get
             {
@@ -93,7 +93,7 @@ public ReadOnlyCollection<Entity> RemovedEntities
             }
             internal set
             {
-                this._removedEntities = value;
+                this._removedEntities = value is ReadOnlyCollection<Entity> list ? list : new ReadOnlyCollection<Entity>(value.ToArray());
             }
         }
 
@@ -115,7 +115,7 @@ public override string ToString()
         /// Gets the collection of <see cref="ChangeSetEntry"/> items for this changeset.
         /// </summary>
         /// <returns>A collection of <see cref="ChangeSetEntry"/> items.</returns>
-        public IEnumerable<ChangeSetEntry> GetChangeSetEntries()
+        public IReadOnlyCollection<ChangeSetEntry> GetChangeSetEntries()
         {
             if (this._changeSetEntries == null)
             {
diff --git a/src/OpenRiaServices.Client/Framework/EntityConflict.cs b/src/OpenRiaServices.Client/Framework/EntityConflict.cs
index cfc15be04..ff211423d 100644
--- a/src/OpenRiaServices.Client/Framework/EntityConflict.cs
+++ b/src/OpenRiaServices.Client/Framework/EntityConflict.cs
@@ -103,7 +103,7 @@ public Entity StoreEntity
         /// <summary>
         /// Gets a collection of the property names in conflict.
         /// </summary>
-        public IEnumerable<string> PropertyNames
+        public IReadOnlyCollection<string> PropertyNames
         {
             get
             {
diff --git a/src/OpenRiaServices.Client/Framework/ILoadResult.cs b/src/OpenRiaServices.Client/Framework/ILoadResult.cs
index 235a7e1ca..67379634d 100644
--- a/src/OpenRiaServices.Client/Framework/ILoadResult.cs
+++ b/src/OpenRiaServices.Client/Framework/ILoadResult.cs
@@ -13,13 +13,13 @@ interface ILoadResult
         /// entities referenced by the top level entities. The collection returned implements
         /// <see cref="System.Collections.Specialized.INotifyCollectionChanged"/>.
         /// </summary>
-        IReadOnlyCollection<Entity> AllEntities { get; }
+        IReadOnlyList<Entity> AllEntities { get; }
 
         /// <summary>
         ///  /// Gets all the top level entities loaded by the operation. The collection returned implements
         /// <see cref="System.Collections.Specialized.INotifyCollectionChanged"/>.
         /// </summary>
-        IReadOnlyCollection<Entity> Entities { get; }
+        IReadOnlyList<Entity> Entities { get; }
 
         /// <summary>
         /// Gets the total server entity count for the query used by this operation. Automatic
diff --git a/src/OpenRiaServices.Client/Framework/Internal/MetaType.cs b/src/OpenRiaServices.Client/Framework/Internal/MetaType.cs
index 31914d516..e223b6d1a 100644
--- a/src/OpenRiaServices.Client/Framework/Internal/MetaType.cs
+++ b/src/OpenRiaServices.Client/Framework/Internal/MetaType.cs
@@ -31,12 +31,13 @@ public sealed class MetaType
         /// </summary>
         [ThreadStatic]
         private static Dictionary<Type, MetaType> s_metaTypes;
+        private readonly MetaMember[] _keyMembers;
         private readonly bool _requiresValidation;
         private readonly bool _requiresObjectValidation;
         private readonly Type[] _childTypes;
         private readonly Dictionary<string, MetaMember> _metaMembers = new Dictionary<string, MetaMember>();
-        private readonly ReadOnlyCollection<MetaMember> _dataMembers;
-        private readonly ReadOnlyCollection<ValidationAttribute> _validationAttributes;
+        private readonly MetaMember[] _dataMembers;
+        private readonly ValidationAttribute[] _validationAttributes;
         private readonly Dictionary<string, EntityActionAttribute> _customUpdateMethods;
 
         /// <summary>
@@ -121,13 +122,13 @@ select attribute
 
             this.Type = type;
 
-            _validationAttributes = new ReadOnlyCollection<ValidationAttribute>(this.Type.GetCustomAttributes(typeof(ValidationAttribute), true).OfType<ValidationAttribute>().ToArray());
+            _validationAttributes = this.Type.GetCustomAttributes(typeof(ValidationAttribute), true).OfType<ValidationAttribute>().ToArray();
             _requiresObjectValidation = _validationAttributes.Any() || typeof(IValidatableObject).IsAssignableFrom(type);
             _requiresValidation = _requiresValidation || _requiresObjectValidation;
 
             // for identity purposes, we need to make sure values are always ordered
-            KeyMembers = new ReadOnlyCollection<MetaMember>(_metaMembers.Values.Where(m => m.IsKeyMember).OrderBy(m => m.Name).ToArray());
-            _dataMembers = new ReadOnlyCollection<MetaMember>(_metaMembers.Values.Where(m => m.IsDataMember).ToArray());
+            _keyMembers = _metaMembers.Values.Where(m => m.IsKeyMember).OrderBy(m => m.Name).ToArray();
+            _dataMembers = _metaMembers.Values.Where(m => m.IsDataMember).ToArray();
 
             if (!_requiresValidation && HasComplexMembers)
             {
@@ -235,12 +236,12 @@ private static Dictionary<Type, MetaType> MetaTypes
         /// Gets the collection of key members for this entity Type.
         /// The entries are sorted by Name for identity purposes.
         /// </summary>
-        public ReadOnlyCollection<MetaMember> KeyMembers { get; }
+        public IReadOnlyList<MetaMember> KeyMembers => _keyMembers;
 
         /// <summary>
         /// Gets the collection of data members for this Type.
         /// </summary>
-        public IEnumerable<MetaMember> DataMembers => _dataMembers;
+        public IReadOnlyList<MetaMember> DataMembers => _dataMembers;
 
         /// <summary>
         /// Gets the collection of association members for this entity Type.
@@ -256,7 +257,7 @@ public IEnumerable<MetaMember> AssociationMembers
         /// <summary>
         /// Gets the collection of child types this entity Type composes.
         /// </summary>
-        public IEnumerable<Type> ChildTypes => this._childTypes;
+        public IReadOnlyCollection<Type> ChildTypes => this._childTypes;
 
         /// <summary>
         /// Gets a value indicating whether the Type requires any Type or member level
@@ -279,7 +280,7 @@ public IEnumerable<MetaMember> AssociationMembers
         /// <summary>
         /// Gets the Type level validation attributes for the underlying Type.
         /// </summary>
-        public IEnumerable<ValidationAttribute> ValidationAttributes => _validationAttributes;
+        public IReadOnlyCollection<ValidationAttribute> ValidationAttributes => _validationAttributes;
 
         /// <summary>
         /// This recursive function visits every property in the type tree. For each property,
diff --git a/src/OpenRiaServices.Client/Framework/LoadOperation.cs b/src/OpenRiaServices.Client/Framework/LoadOperation.cs
index 1d1e929e2..6f01a0a08 100644
--- a/src/OpenRiaServices.Client/Framework/LoadOperation.cs
+++ b/src/OpenRiaServices.Client/Framework/LoadOperation.cs
@@ -60,7 +60,7 @@ private protected LoadOperation(EntityQuery query, LoadBehavior loadBehavior, ob
         /// Gets all the top level entities loaded by the operation. The collection returned implements
         /// <see cref="System.Collections.Specialized.INotifyCollectionChanged"/>.
         /// </summary>
-        public IReadOnlyCollection<Entity> Entities
+        public IReadOnlyList<Entity> Entities
         {
             get
             {
@@ -78,7 +78,7 @@ public IReadOnlyCollection<Entity> Entities
         /// entities referenced by the top level entities. The collection returned implements
         /// <see cref="System.Collections.Specialized.INotifyCollectionChanged"/>.
         /// </summary>
-        public IReadOnlyCollection<Entity> AllEntities
+        public IReadOnlyList<Entity> AllEntities
         {
             get
             {
@@ -232,7 +232,7 @@ public LoadOperation(EntityQuery<TEntity> query,
         /// entities referenced by the top level entities. The collection returned implements
         /// <see cref="System.Collections.Specialized.INotifyCollectionChanged"/>.
         /// </summary>
-        public new IReadOnlyCollection<TEntity> Entities
+        public new IReadOnlyList<TEntity> Entities
         {
             get
             {
diff --git a/src/OpenRiaServices.Client/Framework/LoadResult.cs b/src/OpenRiaServices.Client/Framework/LoadResult.cs
index 761e8650b..fec4c57ac 100644
--- a/src/OpenRiaServices.Client/Framework/LoadResult.cs
+++ b/src/OpenRiaServices.Client/Framework/LoadResult.cs
@@ -16,7 +16,7 @@ namespace OpenRiaServices.Client
     /// <typeparam name="TEntity">The type of the entity loaded.</typeparam>
     public class LoadResult<TEntity> : IEnumerable<TEntity>, ICollection, ILoadResult where TEntity : Entity
     {
-        private readonly ReadOnlyCollection<TEntity> _loadedEntites;
+        private readonly Data.ReadOnlyObservableLoaderCollection<TEntity> _loadedEntites;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="LoadResult{TEntity}" /> class.
@@ -38,7 +38,7 @@ public LoadResult(LoadOperation<TEntity> loadOperation)
         /// <param name="entities">Top level entities loaded.</param>
         /// <param name="allEntities">All entities loaded.</param>
         /// <param name="totalEntityCount">The total entity count.</param>
-        public LoadResult(EntityQuery<TEntity> query, LoadBehavior loadBehavior, IEnumerable<TEntity> entities, IReadOnlyCollection<Entity> allEntities, int totalEntityCount)
+        public LoadResult(EntityQuery<TEntity> query, LoadBehavior loadBehavior, IEnumerable<TEntity> entities, IReadOnlyList<Entity> allEntities, int totalEntityCount)
         {
             _loadedEntites = (entities as Data.ReadOnlyObservableLoaderCollection<TEntity>) ?? new Data.ReadOnlyObservableLoaderCollection<TEntity>(entities.ToList());
 
@@ -51,13 +51,13 @@ public LoadResult(EntityQuery<TEntity> query, LoadBehavior loadBehavior, IEnumer
         /// <summary>
         /// Gets all the top level entities loaded by the operation.
         /// </summary>
-        public IReadOnlyCollection<TEntity> Entities { get { return _loadedEntites; } }
+        public IReadOnlyList<TEntity> Entities { get { return _loadedEntites; } }
 
         /// <summary>
         ///  Gets all the entities loaded by the operation, including any
         /// entities referenced by the top level entities. 
         /// </summary>
-        public IReadOnlyCollection<Entity> AllEntities { get; private set; }
+        public IReadOnlyList<Entity> AllEntities { get; private set; }
 
         /// <summary>
         /// The <see cref="EntityQuery"/> for this load operation.
@@ -105,8 +105,7 @@ public LoadResult(EntityQuery<TEntity> query, LoadBehavior loadBehavior, IEnumer
         protected object SyncRoot { get { return ((ICollection)_loadedEntites).SyncRoot; } }
         object ICollection.SyncRoot { get { return this.SyncRoot; } }
 
-
-        IReadOnlyCollection<Entity> ILoadResult.Entities => this.Entities;
+        IReadOnlyList<Entity> ILoadResult.Entities => this.Entities;
 
         /// <summary>
         /// Returns an enumerator that iterates through the collection.
diff --git a/src/OpenRiaServices.Client/Framework/QueryCompletedResult.cs b/src/OpenRiaServices.Client/Framework/QueryCompletedResult.cs
index 7995b1b0f..96e19a0d9 100644
--- a/src/OpenRiaServices.Client/Framework/QueryCompletedResult.cs
+++ b/src/OpenRiaServices.Client/Framework/QueryCompletedResult.cs
@@ -47,7 +47,7 @@ public QueryCompletedResult(IEnumerable<Entity> entities, IEnumerable<Entity> in
         /// <summary>
         /// Gets the entities returned from the query
         /// </summary>
-        public IEnumerable<Entity> Entities
+        public IReadOnlyCollection<Entity> Entities
         {
             get
             {
@@ -58,7 +58,7 @@ public IEnumerable<Entity> Entities
         /// <summary>
         /// Gets the included entities returned from the query
         /// </summary>
-        public IEnumerable<Entity> IncludedEntities
+        public IReadOnlyCollection<Entity> IncludedEntities
         {
             get
             {
@@ -81,7 +81,7 @@ public int TotalCount
         /// <summary>
         /// Gets the validation errors.
         /// </summary>
-        public IEnumerable<ValidationResult> ValidationErrors
+        public IReadOnlyCollection<ValidationResult> ValidationErrors
         {
             get
             {
@@ -89,4 +89,4 @@ public IEnumerable<ValidationResult> ValidationErrors
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Test/OpenRiaservices.EndToEnd.Wcf.Test/Data/ServerSideAsyncTests.cs b/src/Test/OpenRiaservices.EndToEnd.Wcf.Test/Data/ServerSideAsyncTests.cs
index cf3662a19..1bc89b5b4 100644
--- a/src/Test/OpenRiaservices.EndToEnd.Wcf.Test/Data/ServerSideAsyncTests.cs
+++ b/src/Test/OpenRiaservices.EndToEnd.Wcf.Test/Data/ServerSideAsyncTests.cs
@@ -346,7 +346,7 @@ public async Task Insert_TaskAsync()
 
             // Verify
             Assert.AreEqual(42, rangeItem.Id);
-            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.AddedEntities);
+            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.AddedEntities.ToList());
         }
 
         [TestMethod]
@@ -382,7 +382,7 @@ public async Task Update_TaskAsync()
 
             // Verify
             Assert.AreEqual("updated", rangeItem.Text);
-            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.ModifiedEntities);
+            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.ModifiedEntities.ToList());
         }
 
         [TestMethod]
@@ -421,7 +421,7 @@ public async Task EntityAction_TaskAsync()
 
             // Verify
             Assert.AreEqual("custom updated", rangeItem.Text);
-            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.ModifiedEntities);
+            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.ModifiedEntities.ToList());
         }
 
         [TestMethod]
@@ -457,7 +457,7 @@ public async Task Delete_TaskAsync()
             var result = await ctx.SubmitChangesAsync();
 
             // Verify
-            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.RemovedEntities);
+            CollectionAssert.AreEqual(new[] { rangeItem }, result.ChangeSet.RemovedEntities.ToList());
         }
 
         [TestMethod]