I've run straight pipes for years and yes I think you lose some bottom end. Running down the road empty, I never notice it. Hooked to a trailer, or a heavy load in the bed, I do. Is it enough to bother me, nope. The sound is just what I like. Deep at idle and really screams when you get into it. IMO the systems that people pay tons of money for are no better than what I have. If I towed all the time, or carried a bed full of heavy stuff a lot, I probably would have left the truck stock. Or, I would change the gearing. You don't lose back pressure. The 4 cats keep that in check. Good luck with your decision.