I purchased this truck at less than 50,000 miles. I knew the previous owner, who was fanatical regarding maintenance. I am very proactive with maintaining it as well.
Inner and outer door handles are poorly designed and cheaply constructed; aftermarket replacements even more so. Be gentle opening the door in cold weather.
Alternator, twice, at 56,000 and again at 94,000. Poor Delco design on this model. Supposedly can be retrofitted with a more dependable alternator.
The shock mount broke off of the passenger side lower control arm at 85,000 miles; the factory weld missed about 75% of the joint. Literally, half an inch of a two inch weld was actually joining both pieces of metal. Easy fix, POOR QC.
Intake gaskets 93,000 miles, Dex-Cool is problematic, though GM will not admit to it, even post class action. I noticed I was slowly losing coolant, then parked the vehicle for about three months while I was away on business. Checked the oil when I came back and it was way above the "full" range (fortunately I did not just jump in and fire it up). The oil pan was full of coolant, which is very corrosive to engine bearings. Spent a day and a half cleaning the engine out and replacing the intake gaskets. Apparently a common problem; Fel-pro even makes a set of replacement gaskets they call the "problem solver" for this application. Chevrolet supposedly "updated" their own intake gaskets for the Vortecs as well. I now REFUSE to use Dex-Cool in any vehicle. It can also eat through the plastic intake manifolds; I've replaced two engines on other GM vehicles of the same era because of this. If you must use it for warranty, ensure the system never gets air in it, and I'd recommend changing it way before the ridiculous factory service interval.
Steering; Pitman arm 88,000 miles. Replaced with Moog, another "problem solver" labeled piece.
Climate control switch, 85,000. Poor switch design, fan speed switch went on mine, another common problem.
Inflatable lumbar supports in seats leaked, sometime before I owned the truck. Found the leak and fixed.
Push button 4x4 switch, 92,000, another poorly designed switch, I doubt it had 300 cycles before failure. How many times do the $2 light switches in your home get turned off and on in just one month? GM thinks you should pay them about 35 times that for their failure prone switches.
Wiper motor failed at 64,000 miles. Not the least bit cool when moving 60mph down a two lane road in pouring rain.
I will probably keep the truck as I'm a capable mechanic. It's now over 15 years old, but still has under 100K on it. For what I could sell it for, I could not replace it with anything that wasn't worn out. This will however be the last GM vehicle I will ever own. Unless GM corporate comes around and begins to stand behind their product.
Overall it's decently executed as a light duty pickup. It drives nicely down the road, has very comfortable seats and generally performs as intended. The engine is smooth, makes more than adequate power and delivers decent mileage when driven conservatively; I often get 13-14 stop and go, and around 20 highway.
The brakes and ABS work decent when the truck is not carrying a heavy load. The brakes are inadequate for towing anything but the lightest of trailers; use caution and drive well ahead of yourself.
Again I will keep this vehicle only because I cannot replace it with something that isn't worn out for what it's now worth. It is however the last GM product I will ever own. When I have a Toyota car from the same year with three times the mileage that gets less maintenance, and was actually built in the US and doesn't give me any problems, I find it very difficult to remain loyal to GM.