Yeah. As I said about ut2004, it's just a patchwork and a mess of stupid things, crazy quilt, ut2003 was darker even than ut2004.
I wouldn't even count it into series, it is just raped ut2003 content with added some restored beta maps and then some already released community work and then unrelated teams working on a new content and the singlplayer is really horrible, it doesn't have even a new image for assault at all and the concept is just ut2003 with that and that difference (team roster choosing is done worse than at ut2003, it goes back to the beta concent, but ell that was unfinished), plus credit system taken from ut2003 beta and i would say worsened, credits were not required there at all, they were just as a cool bonus or something and at final ut2003 is no credits in the ladder. I mean credits as the money stuff.
Ut2003 played much better anyway and even custom stuff for ut2004 isn't that high in few exceptions. OMG OMG COLORS COLORS IN UT2004!!!!!
Oh god, that graphics suck balls and the engine being optimized betetr than ut2003? No, that is a lie. In fact with bots it lags as hell and even some maps were proven to be unstable.