I just sold my 05 3500 DRW to a good friend. I loved the truck, and only had one minor problem with the turbo in the first year. It was fixed under warranty and I never had any more problems with the truck or the engine. I consistently averaged 14.5 MPG but most trips were city/rural. It only saw the highway when we towed.
My 05 definitely had fiberglass fenders, as the bollard in the drive through taught my wife a valuable lesson about rear-end cheat. The only complaint I had about the 05 Auto Tranny was the lack of aftermarket or factory exhaust brake. I waited for most of 2005 for Jacobs to produce a brake. The problem, as I understood it, was the engine and tranny computer were new for 05 and not worth the engineers time to crack the coding for an EB. If you do end up with an 05, be aware of the EB issue.
Otherwise, it was a great truck that I will sorely miss. The only reason we sold it was because the quad cab was getting a little tight for the two boys and two dogs. That and the trailer we just bought is 2000 pounds too heavy for the two rating.
I just picked up a 14 Ram 3500. I was very satisfied with everything about the 05, that I went back to Ram without hesitation.