This thread seems to be about nit-picking, IMO. I have drove dozens of these trucks in my line of business and EVERY SINGLE ONE has had good throttle response. Maybe there are some out there with an issue but in my experience they must be far and few in between.
Did the muffler delete at about 700 miles and by a thousand that damn valve started rattling like crazy during cruising speeds. Gonna go with a Magnaflow with dual outlet and regular chrome tips out the rear. Screw that piece of crap valve.