I have driven 119000 km construction usage. Only major problem: Clunking transmission. Cost 2000 to fix. GM paid half. Repair was done at about 70000km, just beyond warranty. OK since. If you notice any tranny clunk, insist dealer fix under warranty. Don't wait around like I did. 6 litre engine is flawless. Front end has never been touched-still tracks straight. I just did front brakes for the first time. The old pads were fine, but I rplaced them anyway. My 95 GMC needed front brakes every 40000 km, my '90 Suburban-every 25000km. I will buy GMC again.
I like every thing about this truck except that the gas guage has never worked properly.The transmision temperture guage also does not work. I took it in to the dealership for repairs and they told me they had to replace the instrument cluster and they did not guarantee that it would solve the problem. A co-worker had the same problem with his. I expect better reliability then this from a 2000 year model.