OSX users are perceptive enough about the nuances of cocoa that recreating all the UI quirks and what not is a huge undertaking. If I had my sanity intact, I would just stick to cocoa.
Aura doesn't attempt to recreate the UI quirks of the host platform.
Exactly my point. To not do so is a crime on osx.
How is it a crime on OSX and not on Windows or Linux. I'm not understanding your point.
I used to be more religious about this sort of thing... but the religion falls apart even on OS X when you realize that even WebKit implements its own copy of the native controls that can appear in web content - so that they can be transformed and animated using CSS.
Yes, OS X is a must have. I actually think 'mobile' platforms like Android should be supported too if you're doing a cross platform GUI thing.