I think UT2004 was more than slightly overrated, but not terribly. Yes, it's a good game, yes it's got good graphics (at the time anyway), yes it's more fun than a barrel of monkeys, but no, it isn't Halo. (BIG fan of Halo, maybe even to the point of fanboishness, but alas, I digress)
The indoor architecture is horrible. Like this one time, I passed up this room with like 3 hunters in it. You know what I did? I walked around the room. Do the designers actually expect you to fight them?
I do believe I know which room you're talking about: The Silent Cartographer, Security Override Room. The way Bungie developed Halo was unique in it's day. Bungie, IMHO, developed the game in a way that you could either run your butt off dodging plasma discharges, or go in, AR ablaze, mowing down every covenant b*****ds as the Forefunner installation can hold. Not like Oblvion or KOTOR, but.... You'll notice in Halo 2, you can't do that, you actually do have to kill all of the Covenant to proceed. Either way, I prefer the run and gun, but some people don't...