I can't get myself to use the light effects because there's some things I like and some I strongly dislike. Generally I like to keep my Doom on the conservative side
What I really like: the static light sources (candles, torches etc) add great atmosphere to the geometry
What I find irritating (doesnt integrate well with my feel of Doom): things like fireballs. The contrast from modern and traditional just becomes to obvious (also for example I dislike the high-def blood splatter some addons provide because they look out of place on low-def wall textures).
Also really annoying: the muzzle flash lights.
So it would be nice if there were settings to control that.