My 2005 has been the best rig I have ever owned. I have been trying to find another one and there are slim pickens under 200,000 miles.
I'd say the biggest issue is the HVAC system and the cluster solder/stepper motors.
Same here. My 2005 Z71 with over 175k miles has been a great, reliable vehicle with zero major problems and no engine or transmission problems. Some relatively minor issues have been a/c compressor, gauge cluster (common problem on GM trucks), EVAP system, Bose speakers, NAV system, window regulator/switch, and transfer case range select sensor.
EDIT: I’ve run nothing except Michelin AT/2 tires on all my Tahoes. The last set cost over $1,200. You can factor that into the price you are paying.