I just finished installing my new steering wheel controls and had it programmed at the local GM dealership. The install took about 2.5 hours. We had some problems routing the new harness, but then we realized that we one plug in the wrong place!! But after that it was smooth sailing. Taking your time and really looking at it helps a lot. The actual programming took the dealer about 1 hour. Everything works on the DIC, odometer, trip, stereo controls, vehicle settings etc. The only thing I don't have is Instant fuel economy, but I'm not 100% sure if these trucks have that anyhow. Perhaps someone else can chime in on that.
The upgrade is definitely worth it!!