I just spent the better part of 2004 shopping for a new Crew Cab diesel.
Ideally, I wanted a truck with the looks of the Ford, the Cummins engine of the Dodge, and the Allison transmission of the Chevrolet. No such animal.
I looked at each of the Big 3, and dismissed the Dodge early on for a few reasons. #1 was their crappy transmissions. I have a friend who owns a shop, and he said that although Dodge Cummins diesel motors run forever, their trannys last maybe 40k miles, especially when hooked up to the powerful diesel. #2 was the cheap feeling of the interior, especially the seats. #3 was the small crew cab compared to the Ford and Chevy.
I really liked the looks and comfort of the Ford, but didn't want to be a guinea pig with their relatively new 6.0 diesel and brand new transmission. That turned me off.
I ended up with the Chevrolet Duramax with the Allison tranny. While the Duramax is very fast and strong, I hear about injector failures in the new LLY motor (which I have). No problems for me thus far, but I only have 5k miles on her. The Allison transmission is awesome, though.
Good luck in your search.
Bud