Had an 07. 5 6. 7 for 3 years, 41K miles, 80% city driving and 20% towing a camper... ZERO problems
Have had sig truck for 2 years, 51K, 10% heavy snow plowing in winter, 20% pulling a 10K camper, and 70% hwy driving (don't live in the city any more)... ZERO problems.
92K trouble free miles so far with the 6. 7.
Get the 6. 7. It's the diesel truck equivalent of an Apple Mac Computer... IT JUST WORKS... every time... every day!
The Chevy Duramax is pretty good... works good most of the time like Windows 7 or XP. The Ford Powerjoke is full of bugs like Windows Vista... a piece o crap!