Just clocked 1000 hrs of run time on my 07 Tahoe, at 33674 miles and 2 years 3 month ownership. I am still averaging about 17 MPG on my 5.3L, have had 4 oil changes with Mobil1 in that time.
Have had no issues other then a leak at the AC fill fitting, fixed first week of purchase and had the battery replaced 31256 miles or exactly at 2 yrs under warranty...
I have the oil changed at the dealership and the tires rotated at every oil change, also has the spline shaft lubricated at the battery replacement for the notorious "clunk" when coming to a stop...

I have been very happy with it, and have logged many a road trip mile in that time, the longest road trip has been from Austin (Tx) to Los Angeles (Disney land)