My friends who have EcoBoost F150's are REALLY happy with their trucks. My friends with 5.0s are also REALLY happy with their trucks. My co-worker with the 3.7L in his F150 (company truck) says he likes his old ('09?) F250/5.4L better.
I do agree that the EcoBoost won't be any more fuel efficient than the 5.0 when it's working had, be it towing, putting a lift and big tires on it, or driving around town with a lead foot. But the EcoBoost has a superior torque-curve, and that's a simple fact. And I'm certainly jealous of its fuel economy empty compared to my V10.