So far, I have had really good experience with my 2015 F-350 DRW Lariat LB. Have had it only about 6 months and 5,000 miles but no problems. Excellent MPG towing my 5th - usually around 15-16mpg at 65mph. Towing with a tail wind, I've gotten almost 18mpg
, but with a stiff head wind only about 11mpg
. Don't do much passing other vehicles, but while towing, I can still get away pretty quick at stop lights.
Personally, I don't like the back seat configuration. It's roomy and comfortable for passengers, but DW likes to haul stuff in the back seat and not much room due to the under seat storage compartments. My last Ford truck had the same fold-up seats but no compartments built-in under the seats which was great for loading in containers, etc.
any of these guys towing at getting 7-8 mpg
http://www.fuelly.com/
Not sure I would buy another dually long bed truck. Lots of good points such as stability on the road, but really hard getting through a "Kentucky Fried "