I think it is quite fun - but would be more fun to shoot each other. I am currently not doing so well against 20 bots at the adept level - but below that I am killing.
I could play this evening. I've started getting back into Oblivion with the Shivering Isles expansion, so UT3 (or L4D) would be a good break from that sort of thing.
Excellent news! It really is a good game. It does take a little while to get through the initial dialog heavy sequences, but once you're out and about it's pretty easy to get sucked in.