Bought an 08 Duramax 4x4 last month and just love the this truck. Ride is very predictable for a 3/4 ton, little harsh but if you wanted a smooth ride go with the 1/2 ton. The diesel has got a lot of horsepower. I love the quick acceleration this truck offers. I pull a trailer that goes about 6000 lbs. If you're looking for a truck to tow and gets generous fuel economy this is the truck.
The new outside style and interior are my favorites. Dual electric seats up front is great and large trailer mirrors work great. I think GM hit a home run with this truck. I get about 17 MPG on the highway
Fold down arm rest for the front seats, and extension in the sun visors would be great.