I've owned the Z71 for about a year and am absolutely satisfied. The ride is extremely smooth and road noise is almost non-existent. The seats are very comfortable (unlike the Ford F- 150 which felt like I was sitting on a slab of concrete). The 5.3 V8 has plenty of get-up-and-go and the mileage is 16.5 city and 19 on the highway. The heated seats are great in Minnesota winters.
Interior room (head and legs) is more than ample. Very smooth ride. The exterior styling gets a lot of compliments. The Bose sound system is very impressive.
More low-end torque would be nice, as takes a moment to get going once you hit the gas. Redesigning the folding rear seats so the rear seat headrests don't wedge into the backs of the front seats would be an improvement.