Another great UT game.
UT2004 is more or less an upgraded version of UT2003 but with way more content.
UT2004 is one of those games you can definately play with a lower end system, but at the same time UT2004 will challege even a high end system at higher settings. UT99 was the same way. I bought a new computer about 3-4 months after it come out, and the game looked like a different version with the new hardware. It was shocking (in a good way).
Snipers may or may not like this game as much. I don't really like the lightning guns (sniper gun w/ zoom). It just never had that 'sniper' feel to it. I'm glad UT2007 is going to go back to its roots and will include gameplay more comparable to UT99.
The vehicles are a lot of fun, and it added that extra 'flair' UT needed to have. All in all this is one of the best games period.