I use an in-terminal editor all the time on OSX, what I like about OSX is that I get the Sexy UI with a lot of the things I have come to love in Linux(at least in a terminal, where I spend much of my time anyway)

I use OS X because I can keep my dev workflow while getting much nicer applications for everything else.

There's also Aquamacs. Seems to work quite fine.

My memories of Aquamacs are full of fighting with the thing to do what I wanted. It was overriding everything I customized in my .emacs.

About the only positive thing I found about it was the ability to run in full-screen mode (something that ntemacs is still unable to do).

Indeed. But it's not like using Emacs on any other platform.

OK. I do not use it myself. But my fiancee has a Mac and seems quite happy with Aquamacs. (She used Emacs on Ubuntu before for some time, to do LaTeX with.)