I just started playing it,
It's fast paced, insanely addictive and you can play against people in several different time zones.
Crisp graphics, a good assortment of weapons and all the content you could want.
As far as an FPS goes, it simply deliverers.
Don't give a rats ass what I think? thats fine, download the demo for yourself and find out: http://www.chem.crapness.com/ut2003demo2206.exe
While I hate to sound like a frothing fanboy, the insane gameplay really gives what you want out of a FPS, and some.