I have used UE on Win, did not particularly like it. TM folks most likely will like it. UE has a similar philosophy as TM.
Multi-Edit (ME) is IMO the best "text editor" on the Win platform. Technically it's an IDE, but barely.
When I moved to Mac, I was sorely disappointed in the selection of programming tools. I actually installed a VM w/windows so I could use ME. The reason I decided to use TextMate, was due to it being the editor that was closest to Multi-Edit, power-wise. However the first thing I thought when I first used TM, was "this is like UE, damn."