As good as the pc version!
Anyway doom 3 is quite a great game with excellent replay value, it is very old school and reminds me of the original DOOM and QUAKE, yet the graphics are absolutely amazing, so amazing that if you see them you would not believe that its running on a xbox. I also really like the feeling of being alone in a dark space station overrun by "hellspawn" and all the other space marines are dead and it just you with your weapons and flashlight. The enemies in Doom 3 are interesting and varied and look and act brutal, some of the enemies for e.g Hell knights are tough and will make you run for your life, the enemies are actually scary and look very real which makes them even more frightening! Doom 3 has a rather weak story about a portal from hell opening and you (a unknown space marine) having to save it from the demons who invade the mars space station. Doom 3 is really more about action and tension than story which is what makes it quite unique, i mean all the levels are so dark and the only thing you have is a rather weak flashlight which you have to swap for a gun to quickly exterminate enemies, getting sorrounded by nightmarish creatures and shooting them in the dark is quite a unique experience. However the game's cramped corridoors and rooms do get a bit dull after playing the game for a long period.
The campaign mode is great, pretty long and higly replayable yet the online mode is a major disaster, its 4 players and yet lags like crazy! The co-op mode is great but overall the multiplayer fails to impress!
Overall i think you should just rent this game, if you do turn of the lights, raise the volume and play by yourself late in the night with no-one around you and get ready to jump!