Just seeking opinions on a used Duramax

I just traded in my 05 lly for a 2011 3500Hd dually. I was the original owner and it had 128,000 miles on it. Never had it in to the shop for anything. Pulled my huge new 5th wheel down the road with no problem other than the 3500lb hitch weight was a little too much for it. I had put the LBZ intake on it, the egr delete, and the PCV re-route. The fan did kick in more than I liked. It had 19.5's, a new Ranch Hand Legend front bumper, air lift air bags, and was still tight. I would not hesitate to drive it anywhere. Any way, it was not 4 wheel drive, which hurt my trade in. I got 12,500.00 for it. Probably could got a bit more if I had not traded, but not much. The dual wheels, LML and 6 speed allison on the 2011 are pretty sweet.....If I were pulling a trailer or smaller 5th wheel I would still have it.