My neighbor has a Ford F150 with the ecoboost engine and pulls a Cougar 29' fifth wheel with it. The truck has the heavy duty payload package along with LT tires in lieu of the P-metric tires. He said it also has heavy duty brakes compared to the standard truck. Pulls and stops the trailer very well, according to him. I have seen him on some hills when we camped together and he has no problem keeping up with traffic. Seems to have good stopping power also. I wouldn't want to do it but he has no issues, as of yet.
Curly