The Aquamacs changes are very annoying if you try to use Emacs on another platform as well; an Emacs configuration that sets up M-x to be "cut" is almost trying to make people's life difficult down the road. Better to swallow the bitter pill right up front and learn to C-w and C-y like everyone else. (Or A-x and A-v if you really can't do without something vaguely familiar.)

That said, once all the silly defaults are disabled and the standard Emacs behaviour is restored, it's arguably a better Emacs port than Carbon Emacs, and thus is what I use when I'm working on a Mac.