Try romping on it in the manual mode instead of in drive and see what you think.

Try romping on it in the manual mode instead of in drive and see what you think.

If the dealer is unable/unwilling to find anything wrong, ask them if you can drive another truck with the same options, if they have one on the lot. If you feel a difference, demand that the dealer do the same comparison, and then fix your truck.
I have the 5.3, and am amazed at the power.

Also, when you are in the rolling hills, does your truck downshift much? If yes, then I'd be more concerned. I am pleasantly surprised at the way mine holds a gear on mid-to long grades. Definitely some good torque there.

If the dealer is unwilling to work with them shame on them. They should do anything in there power to help you after the sale is complete as well, not just to make the sale.I would give them another shot. If they still brush you off. I would call GM cares line. I would tell them that you feel like you were shown false hope as they treated u differently before the sale to after the sale. Your concerns and issues should be treated the same to as if u were a person test driving a new vehicle or a long time customer. If your not happy or concerned they should be more than willing to do what it takes to help you out. Keep us posted on how we can help you out

well custom tuner (SCT from More Power Tunig) and a 87 octane economy tune took care of everything.

Tried to go to toptier.com and found out it was toptiergas.com. Pretty interesting site though, thanks for the heads up Wingnut.