The GMC Sierra 1500 is a reliable pickup.
Depending upon the miles, it can make or break the pickup. Obviously, the lower the better. Still, with the 2007-2013 model GMC or Chevrolet pickups, they tend to have higher miles. Anyhow, they're prone to electrical problems. Also, the Active Fuel Management (AFM) is a serious bummer with these trucks. The AFM shuts off half of the motor, leaving 4 cylinders active. I would highly recommend getting the motor converted to a full V8. This is an expensive, but rewarding process. It involves head work, timing work, a new camshaft lobed correctly for a V8 motor, new lifters, valves, and gaskets. It's possible that there could be more to the process. The pickup is overall very comfortable. I drove 6+ hours with no issues whatsoever. The stock sound system works fine. The radio is perfectly placed. Overall, the pickup is something I would recommend to anyone.