This has been the best truck that I have ever owned. I bought this after selling my 1994 Chevy Silverado, and man is there a difference!
For starters the 5.3 liter turbo'ed Vortec in this thing run so smoothly that you sometimes wonder if it's even running. She starts very smoothly, and has minimal "Chevy Knock" in the lower body.
My particular model has the SLT trim package with leather interior, OnStar, and the BOSE sound system. OnStar is a bit of a letdown as they went digital in 2007, and to upgrade to a digital reciever costs some 300+ dollars! The BOSE sound is great, and includes a 6-disc in dash CD changer, and a 8 inch amplified subwoofer in the middle console.
The biggest problem that I have had with this truck is the battery and electrical system. I have had to replace the battery twice, and both times with Redtops, so I know that they are quality batteries. The reason that the batteries keep dieing, as I have been told, is the beefy sound system in this thing, which does indeed draw about 22-25 amps when running.
Another problem I have had is with the tailgate cables. My truck was equipped with the recalled steel cabling that had a problem with oxidation. Mine did indeed fail and break, but the GMC dealer was a great help in getting me a replacement pair at no cost to me.
The headlamp burnout and rear greasing I chalk upto maintenance, and were really more of an annoyance than a major problem.
Just FYI, this is indeed a work truck. I own an air conditioning company, and drive this as both my work vehicle, and as my pleasure and day-to-day vehicle 7 days a week.
All in all, this has been THE best truck that I have ever had in a long line of Chevy/GM vehicles, and I would definitely buy another when the time comes!