I had an '11 F150 5.0, I pulled a car trailer hauling a Mustang, as well as a 21' TT. It pulled both with power to spare and delivered decent MPG, mid 9's-10. We had zero problems with the truck over 100K miles, traded it for a 6.7 F250 when we got a larger RV.
While the V6 delivers lots of power, there seems to be a lot of talk regarding turbo longevity and of course the infamous cam phasers, both of which are greatly affected by how often the oil was changed, so if any candidates don't have solid maintenance records, I would pass.