When I used Textmate on my Macbook and Notepad++ on my Windows PCs, I always had issues with indentations, and stuff from one editor to the next. I also used to have to setup Samba on my Ubuntu server to map the network drives, and edit them over a mapped drive.
Once I found Eclipse to be as awesome as it is, I don't think I'll ever look back. lol.
Since the OP is on a Mac due to TextMate, this link may be essential: http://www.mdimension.com/page/Maclipse
If you don't have a history of vim mastery, you should still think about it. Yehuda Katz wrote an interesting blog article[1] on his experience switching to MacVim as a vim beginner relying on OSX-isms.
1. http://yehudakatz.com/2010/07/29/everyone-who-tried-to-convi...
I personally found it best to just embrace the vimness (with cheat-sheets beside my monitor). I barely accomplished any work on day 1, but by the end of day 2 I was moving along pretty comfortably.
I posted some screenshots of my setup here: http://news.ycombinator.com/item?id=2053516
Using tmux instead of normal terminal tabs is also a huge improvement.
It also costs $100 (though it is on sale right now) where Eclipse costs $0. Not an insignificant fact for many of us.
I don't mind buying good software. Unless you're developing OS without any benefits any speed increase would lead to benefits increase (well, not any, but you know).
For a solid IDE, Netbeans. I find it easier to use than Eclipse.