I think this game deserves no praise. It can hardly render more than 2-3 enemies at once, the looks are not that stunning, because you usually see cramped, narrow rooms and close combat with the same Imp that gets created by a trigger in your back over and over.
Gameplay is also a step backward, even compared to the old Dooms. For atmosphere, I found playing as a Marine in Aliens vs. Predator creepier.
But if someone is interested in seeing how this game runs and looks, high detail, no AA:
http://www.longasc.de/stuff/doom3.zip
Radeon 9800 Pro, Athlon 64-3000, 1024 MB RAM.
On my P4 2,8 with 1 GB RAM and Ti4400 it runs not so good, regardless if low or high texture detail - resolution is important for framerate, unusual today.
Note that it is black in black. I recommend increasing gamma and making the monitor brighter.
This game might appeal to a horror crowd, all others will quickly get bored by a repetitive and not really good looking shooter. There are many games out that have more impressive Visuals and larger maps, like Far Cry and Joint Operations. UT 2004 is even capable of having more than 4 players on screen in Multiplayer without getting framerate issues.
So what the fuss about this game. It is a big letdown.