I picked up my Mineral Grey 1500 Sport Quad Cab with RamBoxs two weeks ago. I have put about 1300 miles on so far and I saw an average MPG (this is since I picked it up) of 20.9 and its been still going up! This is the Hemi 8 speed with 3.55 rear and that includes about a hundred miles of towing a 6,000 lb trailer with 700 lbs of people in the cab. I couldn't be happier with my truck.
Just for reference I previously had a RC Dakota sport with a v6 for 8 years. It got barely 18 MPG rounding up on pure highway miles. So I got a lot more truck, a heck of a lot more power and 3 MPG more!
The only issues I had found were a missing rubber strip between the bed and the cab on the drivers side and the hood is miss aligned but that'll take 10 minute to fix at the dealer so no big deal. But it did go through the 100 percent/point inspection on the assembly line so hopefully they didn't miss any thing else.
The pics I attached are bone stock the day I picked her up. My three dogs had to inspect the truck, they gave the final approval.
So far I have added a Truxedo Lo-Pro cover and VAS rain guards. And I'm very happy with both of them. I'll have pics in my build thread, might take me a bit to get them posted as my phone takes pics twice the size as what I'm allowed to attach so I have to convert them all. And I'm too lazy to create a Photobucket account right now.
Here is the link to my build thread, hopefully I will update it by tomorrow.