If you do the math, the Ecoboost will have much better performance as will a 5.0L compared to a 6.2L in a similar F250/350. The reason is because the F150 is so much lighter.
A F250 with the 6.2L is about 1200lb more than my F150, same configuration and options. My F150 is 5768 lbs so the F250 would be about 6968 lbs. The 6.2L is rated lower at 385 HP and 405 lbs of torque in a F250 and even more so over 10,000 lbs GVWR. 5768 / 360 HP (5.0L) = 16.02 . 6968 / 385 Hp (6.2L) = 18.1 .
5768 / 380 lbs (5.0L) = 15.18 . 6968 / 405 lbs (6.2L) = 17.2 .
Now that F250 6.2L performance would feel like an engine having 318 Hp and 335 lbs of torque in my F150. That would be like through the old Chevy 5.3L in a F150 (315 hp and 335 lbs of torque). So it won't having the pulling power of your F150 but will have the payload.
You may want the Diesel just to have the higher power on low rpms to make getting going a lot easier. The diesel option adds 500 lbs and is 400 Hp so it will even have a lower HP compared to the 6.2L when weight in figured, but the gobs of torque at low rpms will get the trailer moving a lot faster. It would be like having 618 lbs of torque in my F150 when power to weight ratio is figured.
5768 / 18.1 = 318.7 Hp . 5768 / 17.2 = 335.3 lbs of torque
