I am looking at trailers in that size range, and I started out looking at F150s but ended up opting for a Cummins Ram. I don't really see much disadvantage in day to day use with the diesel vs the ecoboost. I guess it's a little slower off the line, but it's plenty quick for my purposes. I think it looks better, and it's certainly a more stout and capable platform. The up front cost is very comparable, and I'd wager I get better mileage both towing and unloaded based on the real world reports I've heard on ecoboost mileage. As a daily driver I've been incredibly happy with my Ram so far. The new F150s are more carlike (too much so imo), but a modern heavy duty truck is a far cry from the primitive beasts of years past. As an aside, I did also look at Powerstrokes and I liked them, but the platform is dated and that's very evident with a short drive, and I trust the Cummins more than a Powerstorke in the long run.
Back to the topic at hand, I know what the towing specs say but for that size trailer there's no way I'd go with a heavy half over an actual heavy duty truck.
To me this is a no-brainer. Go heavy.
