I have a confession to make. While I've benchmarked it and tested it, until the past few days, I haven't ever sat down and really played Doom 3. Since Half Life 2 was released this week, I thought it'd make a good time to
take the two games head to head and see which came out on top. I've spent a few hours in the beginning of each, playing through the first few levels. Although I haven't completed either, I've spent enough time in each (I think) to develop a feel for what the later sections of each game will be like.