310 HP and 348 lb ft of torque is plenty sufficient for that truck. There are tons of V8 trucks that don't make that much HP and Torque and they do just fine. Sure the 4 cyl probably makes that power high up in the rev range than the V8s, but 1/2 the people buying these trucks are soccer moms anyways.
Personally I think it is pretty cool, and I'm sure Ford and FCA (though FCA usually takes a while to play catch up with the other two) will follow suit.
For soccer moms it should be good.
Peak torque at 1,500 RPM, not bad.
Easy to make torque down low with a turbo.
For the numbers stated that is under optimal conditions in a controlled situation, good luck in the real world. I'm not buying one so I have no skin in the game but good luck to those that do.
Just for the gee-whiz file: I have a work associate that has the first year Ford f-150 Eco-boost that gets worse mileage than most owners of F-250 diesels I know. He drives like a grandma, I've spent plenty of hours in the truck. His isn't much better than another friend's gas F-250.
I think most companies are banking on most people not traveling that far and turning vehicles before the official warranty is up.