I'm slowly getting up to speed with Emacs, switching from TextMate. There are a lot of ways to use emacs on Mac, from Aquamacs to Carbon Emacs to the Cocoa port of GNU Emacs. I've dabbled in each a little bit.
I'm most interested to hear your thoughts on keybinding (and which Emacs distribution you use). I like the thought of keeping Mac shortcuts consistent a-la Aquamacs (having CMD-Q still bound to exit, etc), but it seems like the Option key is too poorly-placed to be a useful Meta key.
(I've bound Caps-lock to Ctrl.) It seems like binding CMD->Meta and CTRL as Control would provide the best placement ergonomically, but obviously you then lose the standard Mac keybindings when in Emacs.
What does your Emacs setup look like?