So apparently the 3.5L EcoBoost in the F150 is a tough lump. Ford put one they randomly selected off the production line through endurance testing at the Cleveland engine plant, put the same engine into a logging truck in Oregon for a while, then used that truck to tow 11,300 lb at high speed around a NASCAR track and do some steep-grade testing against competitive trucks. Then, after what Ford described as 10 years' worth of use, they put it in a Baja race truck and ran the Baja 1000 in just over 38 hours.
Granted, it's just 1 example, but it sounds like the 3.5L EcoBoost may not suck as a truck motor.
Followup: Ford F-150 EcoBoost finishes Baja 1000 in 38 hours — Autoblog