You wouldn't believe how many people still play this game online daily. If you're just now jumping into the series, you're sure to have a fun game right here. This is coming from someone who owns Unreal Tournament 3.
I went back and got this game simply because my hardware could barely handle UT3 and often crashed. I remember constantly playing the demo for this game when I was in highschool, and didn't know what I was thinking not getting it until now. Even though it doesn't look as flashy, this game holds pretty much the same exact gameplay as its sequel, and is possibly even better.
Because its such a old game, you already have access to literally thousands of custom maps to explore. It is incredibly fun to join a server with a large map list and have a different experience every round. You'll always find new ways to go about things because of how many vehicles and weapons there are in this game.
Final word: Don't buy UT3. Save money and buy this.