I used textmate for over a year. I get it, but emacs is more powerful. I decided the painful learning curve was worth it because I use my text editor for at least 8 hours every day. Plus, with emacs I"m not tied to the mac platform and a non free program.
Okay. I have used both extensively: emacs for several months, and then TextMate for the last 2 years, and I find TextMate more powerful. I decided the painful learning curve wasn't worth it, because it made the editor less flexible, and it made what flexibility it does have unpleasant to exploit.
And I'm a certified machead, so that was no object.