Local GM dealer has been good to me, so long as they recognize the problems and repair it for free, i'm good. We have a fleet of over a hundred diesel Fords (and hundreds non diesel) where I work. lots of down time to repair..over and over again. They are the cheaper truck to buy for a fleet, but cost more in the long run. Dealer cannot fix the 6.7 properly and they usually blow up again, took them three tries to fix one F450, they're too complex and the old experienced techs have retired. We are now trying out the Ram 5500 cummins. Unfortunately GM doesn't sell a truck that suits our needs. I can get an amazing deal on an F150 (fleet pricing)... I still wont do it.
Sorry a little off topic. Fix my radiator GM, keep me happy. hopefully the problems taper off. I do like the truck.