I haven't played Doom 3 in years but I didn't think the flashlight mechanic was anywhere near as bad as people made it out to be. There's a few situations where you need to juggle flashlight and gun to see anything, but at that point you should be relying on sound cues to gauge where enemies are. Doom 3 (and specifically how it played a lot with light and shadow) is a big influence on my own design projects.