My mods only change skins for weapons. I have the Dubstep music to replace jukebox and concert, and I have an HD glowing defib that isn't much different from the original; the medkit I use looks like a TF2 dispenser, and a hud icon mod for it, other than that, I don't change the infected/character skins, messes with the storyline, and messes with my head because of that.