The 6.7 liter Cummins tows like a dream. What I really enjoy is that the width of the camper is just about the exact width of the rear of the dually. So when it comes to visual spacing going down the road, it's easy. The engine is outstanding and DOES NOT bog down at all! The real cream rises with the incorporated electric brake controller and the integrated exhaust brake. I also have the 4.10 axle. Towing capacity of my setup is 20,900 lbs. Fully loaded, I am about 15,000. The Mor-Ryde pin box really smooths things out in the bed, and after a few miles, I hardly know it's back there. Good luck with your decision, but I HIGHLY recommend these new trucks.
2012 Jayco Pinnacle 36REQS
2012 Ram 3500 Crew Cab, 6.7l Cummins Diesel, LB, DRW
May God bless America!