5.3L V8 is a damn powerful engine! More so with a few aftermarket goodies. We absolutely love this truck, chose it for being much sexier than Chevy counterpart. I am a street truck enthusiast, and appreciate that the aftermarket is chock full of parts/accessories for my truck/engine. I only marked down on comfort b/c you can find a roomier back seat in a smaller truck (Dodge Dakota Quad Cab). We have two kids in car seats and I am a six-footer, so the back is getting pretty cramped. Also I thought the SLE should have fancier "upgraded" materials in the interior. Fuel economy is not great, but better than you'd expect from an engine that size - a little maintenance goes a long way in this truck.
1) The whine of the air passing through the K&N intake and throttle body spacer. 2) The growl of that 5.3 comin out the Gibson cat-back exhaust. 3) Speed controlled volume on radio is kinda cool too.
You can't improve upon perfection! Unless GMC decides to build them with the 572!