I bought the top model, 3500 HD, crew cab, 4wd, dually with all options. The Duramax is strong and the Allison tranny shifts smooth. Great power with acceptable mileage. The interior is a complete overhaul from the Classic models. The navigation system is addictive and the integrated brake controller is a step in the right direction. Very quiet and great driving. I rate overall a 9 out of 10. No one is perfect.