I have had my Silverado for over a year now with no problems to report. The Duramax/Allison is an absolutely amazing combination, leaves the competition in the dust. My only complaint was the small wheels and tires from the factory. Overall, an excellent built truck period.
Duramax Diesel/Allison 6-Speed Automatic Tranny.
At least an 18" wheel/tire combo or even better a 20" option like the 1/2 ton versions.