I just made my purchase yesterday...
... Silverado High County with the 6.2...
This thing is insane... On the way home from the dealership I was just easing along... I look down and sure enough I'm doing 100 mph.
It sure as hell didn't feel like I was moving anywhere near 100 mph. I'm definitely going to have to use cruise control a lot this thing is smooth and with that 10-speed transmission you don't feel a thing.