For some reason the diesels always do better than EPA combined
(even the non-VW legit diesels), and the EcoBoosts do a bit worse.
My theory is that diesel owners buy them primarily for hwy driving, and EcoBoost drivers just really get a kick out of their turbo (lead foot).
The HP versus mileage issue really is a personal issue highly dependent upon how, what and where you drive. And probably age as well. As I get older and slower, HP has become less important than comfort and mileage.
But if we still had our 4000# trailer and needed a new truck, I would have a hard time deciding between the EcoD and 2.7 EcoB. As I mentioned earlier, payload might actually be the determining factor as we carry a lot of toys in our tow truck.