Having developed in MT and ObjC (but not yet bit the bullet on RubyMotion), I can concur that this statement is valid. MonoTouch was an emulation, making it at best slow to catch up and at worst a version behind iOS. It also had a fairly funky debug scheme, having to use IP and not the wire. Granted, you get the REPL in lieu of a debugger with RubyMotion, but given how incredible the REPL is, I imagine a debugger will follow. As for cross-compilation, that wasn't so much MonoTouch as MonoCross, something that falls in to "jack of all trades, but master of none." MonoDevelop may have autocompletion, but it was buggy as all hell for me, and RM is positioning itself as using any IDE, where MonoDevelop locks you in as Xcode does.