Not currently in my muscle memory but this does interest me since I use vim sometimes for other ocassions. I'd prefer if shift wasn't necessary though... so I'm not sure I'll commit to this :).
Still, these are worse than Mac shortcuts that Komet uses IMO, and I dislike escape (and control to a lesser extent) :-).
Also you sometimes want to quit with an exit failure status on canceling, and why have two different operations for that when your editor is smart enough to have one.