I didn't get that much out of Doom3. There were too many things that just wasn't right about it. For one thing, its to slow. Save your "upgrade then" posts. There were alot of things that could have been better. This game NEEDED mulitiplayer coop above anyother game in recent years. The multiplayer that is sucks donkey dick. To me, graphically the game has nothing over Quake 3 except shadows and lighting, but nothing that impressive. I never could understand how so much texture memory was needed as all the textures in the game look identical.
I did have fun playing it of course, but I'm going to wait for the next few Doom3 patches to see if they at least fix some of the CRAP in it. More maps, some outside sections would be neato to DM in.
I think Carmack is a God, and did kickass work on the engine, but the level designers and other elements of the game kinda sucked ass.