A little of both. My IM barrel has no rib and I wouldn't mind having one. A fella let me run a round with his K20 with a high comb and rib and I could definately tell the difference. A local pawn has one of those crazy looking Mossberg trap guns for sale and I'd try it but for some reason it takes a two hand grip to rack the slide on it.
John A. Monroe, Never Forgive, Never Forget, Blood Pays Blood