This is my 2nd GM diesel truck and it has operated flawlessly since delivery. The power and accelleration for a big truck makes it fun to drive. I tow a 14000 lb 5th wheel and can pass with ease going over the mountains. The mileage is about 10mpg with the trailer and running 65, without it runs about 18-19 mpg on the highway.
This vehicle has surpassed all our expectations (except for the dealer who is mediocre). The cabin noise level is lower than most of the cars that I have owned in the last 15 years. Build quality is improved over the 95 GMC that I owned. I tow 10 to 13K pound loads on a daily basis. Hauling horses I routinely discuss trucks with other guys at horse events. I find that I can out haul them, get slightly better gas mileage and the TRUCK IS IN THE SHOP less than my Ford F350 friends (one of whom has sold his to buy a Chevy 3500). If you are looking for a real work rig, this is it.
We upgraded to a heaveier tow vechile. We have a horse ranch and haul 12,000 to 15,000# trailers. If you want a SERIOUS tow vehicle, this is it. Neither Ford nor Dodge can touch it. It is also eztremely quite, but due to the towing capacity a little hard riding. Build quality is great, especially considering this is a TRUCK