Towed all over the country with two separate F-350s. Great truck. Tow haul mode, dash brake controller. Tranny is problem free after 200,000 miles. New 2016 models of F-350 diesel have transmission brake and engine exhaust brake. I drove to Alaska and back from my home in Maine this past summer, including two times across the Rockies and I can count the number of times I used the foot brake (other than city driving) to stop the vehicle with. As long as you plan ahead, it is not necessary to hit the brakes going down steep inclines or under normal stopping situations. Plenty of power to climb those mountains, also.
I will have another F-350 when this one wares out.
Lakeside