Doom 3 has too much imps, former humans and shotgun sergeants.
But the most annoying thing is all the narrow places, the entire game is a narrow place.
The other monsters and the big rooms are so few they don't even count as part of the game.
If I see a mod that has remakes of the original doom 1/2 maps I'd install Doom 3 again, but the original doom 3 really sucks.