Gameplay hasnt changed much since the original UT in 1999, apart from vechiles, which were added in UT 2004 (came out in 2003).
The game might seem cool and a novelty at first, but after a few days or a week, you will realise that it's a good thing that the industry has moved on to a more tactical based approach rather than just running and blasting everything that moves. Story is pretty much non-existant, yep they actually tried to make a story out of capture the flag. Overall Gears 2 has better graphics, but this still looks better than the original Gears and actually has better textures than both Gears titles on the smaller maps.
Still a decent game, but we're not in 1999 anymore, things have changed. If you must get this game, get the PC version, or if you don't have a half decent machine get the PS3 version. Both versions have free mods to download and the tools to create your own.
I'd give the 360 version around 7.0 out of 10