I'm an ex-UltraEdit user, and I think TextMate kicks it into a corner and calls it names ! The tab commands alone are a huge timesaver - UE never had anything like that when I was using it. UE has also become a bloated mess, whereas a TM window is about as uncluttered as you can get.

Everyone else at my work is using Eclipse. I think they are nuts - why would I want 2/3 of my screen taken up with toolbars and other panes. I like to see as much code as possible, and TM lets me do that. I discover new features almost every day ( eg. the fact you can type a quicksilver style shortcut when using the Command-Shit-T navigator)

The only feature I really wish (every day!) that TM had is split window panes - I frequently need to seem two parts of the same file at the same time.