I recently test drove one for a $50 gift card to Cabelas. The 5.7 liter engine is powerful, and the transmission is very smooth. I thought the ride was a bit too rough (like the Titan). I also thought the nearly $50K price for a half ton truck was a big steep, especially for one that shocked me with the squeaks and rattles and this truck had. I was very disappointed in that, as well as the climate and stereo controls that were too far away from the driver. The door handles had a very flimsy feel on them as well, something that the 07 Silverado/Sierra share (but thats been fixed for 08 as I recently found out) The room in the CrewMax is huge, a homeless man could live back there and be in hog heaven.
I have driven a new Silverado and Sierra as well, and although the one I drove was the Flex Fuel 5.3L, I can't compare the power of the two vehicles since the Silverado I drove. The two GM trucks I drove (both top line LTZ/SLT crew cabs) did not squeak or rattle when going over bumps, and I thought the ride was far superior, and the controls for the radio/HVAC were close to the driver. The prices for the trucks I drove were $41K for the Silverado and $42K for the Sierra. I also felt the redundant controls on the steering wheel were easier to use, despite the fact that there are more of them.
Of all the things I look for in a truck, the GM trucks come out ahead because they offer similar capability in what I need them for, but I cannot stand a vehicle that squeaks and rattles when it is new, especially one with a steep price of near $50K, and with the experience that a few people I know have had with Toyotas, I am leary of their real world quality and reliability.