i own the suburban and the extra cab long bed version of this truck and couldn't be happier.
only quirk is change the fuel pump every 70k and radiator at 200k otherwise flawless and economical.
I baby my trucks as a rule and get 25 m,pg out of my truck and 23-24 out of the suburban. there are plabty of smaller truck I could load in the back of mine and drive around and i would get better mileage moving them that way than just driving them.
oh truck has 300k and suburban has 200 both are still strong and could drive across country with out worry
reliability and comfort. 4x4 is awesome in the heavy sierras snow as well
plan on changing the fuel pump every 70k and do your oil changes.