But not with your previous example : it is around the same speed.
That would therefore suggest that this is more to do with the fact that MaxGUI Canvases and them being different from normal gadgets in as much that they are hardware accelerated graphics contexts being displayed in a software rendered environment (the Windows GUI window). I have little understanding on how this all works internally when Flip is called, but this is all up to the Max2D driver (not MaxGUI).
Anyway, you said yourself that even with my previous canvas example, the new module had around the same speed as the old module, so I suppose I'll have to wait for that code example.