How so? UT3 has four main themes of maps if I recall it correctly. In original UT (without bonuspacks) it was mainly industrial themed (and some boring imo) maps. There are few exceptions, but that is only like one map in the crypt2.utx (which comes orginally from unreal beta and I don't get how would liandri build that cryptic theme map, if it was originally set in Na Pali (special temples built for Skaarj in the cryptic theme by Nali), so that's a weird lie in these map descriptions as well as other weird things, wtf time paradoxes and so on
), one egyptian map, which theme seems again come from early Unreals partially (there were few screenshots with egyptian themed maps while unreal was in developement, although the textures are not same), but again only one map, I think it's a little waste of themes in original UT.
The ut2004 has variety of themes because it contains also most of ut2003 content, but the quality of the new maps aren't that high, they all have pretty much simmilar shapes and are getting boring and I mean it mainly for DM.
EDIT: And btw, skaarj hybrids in UT, to psycho: They had no special voices, the only special sound was the footstep, the other sounds were only pitched already existing voices inside script, no new voices or anything, so basically the skaarj sounds plus male voices in the monster speech, many people don't know about this, I first though it was standalone voice pack, until I looked in the script and that there are no other new sounds than footsteps.
But still even that is better than ut2004 skaarjs.