All I know is my buddy is very happy with his Eco-Boost with 6 speed transmission, but does state he only gets 7 mpg towing his camper or tritoon boat. He does live on the western slope of CO. I don't know what his boat weighs, but the camper is less than 4K lbs.
Last 1/2 ton I owned was a 1990 Chevy Silverado with 5.7L. It pulled decently well with a loaded 16' stock trailer and 18' car hauler, just about 10 mpg. I just had to keep out of overdrive, as the weak link was the 4L60E transmission. Anyway it was a good pickup, put two transmissions in it and one engine but I ran it to almost 400K in 15 years of ownership.
