I tow an X213 with a 2015 F150 supercrew 5.0 with 3.73 gears and it pulls with no problem. I can pass at 75mph. I was looking at the Echoboost too when looking for my truck. I only went with the 5.0 because I got a much better deal. I agree with others, I would look for something with the 3.73 over the lower gear ratio.
If I could go back, I would have looked more for something with th Max Tow package or whatever would give me the highest payload in a F150. My F150 can tow max trailer weight of 9300 lbs but the max payload is 1560lbs. I would have liked to get the max on the payload because with the trailer tongue weight, passangers and whatever I throw in the bed, I can get up to that 1560 pretty easily