The .NET SDK prohibits classes to be derived from CRhinoObject
Operators
VB.NET framework cannot at this time translate operators such as + or * into function calls. You have to use the op_Operator calls like this: OnXform.op_Multiply(OnXForm, On3DPoint). C# on the other hand will permit function calls like On3DPoint myPoint = xform * pt;
MRhinoMouseCallback
This class was never fully implemented. I think this also holds true for the C++ SDK (if I understood it correctly), so it may not be a discrepancy.
MRhinoAnnotationText
This class's SetAnnotation() member function in not available to the .NET SDK. SetAnnotation() is needed due to some code in Rhino that does not allow us to call SetString() instead.
MRhinoSelCommand
Class not available in .NET SDK.
MRhinoTestCommand
Class not available in .NET SDK.
MRhinoDoc.Properties()
This member function is not available in .NET SDK.