For the last 3 years, my 2015 F150 f-door short bed (5.5') 2.7 liter 4WD has been my daily driver. Never intended to put a camper or a bed cover on it and have not. Never intended to tow with it but tried it once and loved the outcome. Our camper is a 2,400 lb dry weight A-frame pop up so it doesn't catch the wind too badly.
As mentioned above, fuel mileage is pretty much what you want it to be depending entirely on how frisky you want to be with the skinny pedal. Empty/lightly loaded, on fairly flat terrain, w/out the A/C running, no headwind, and held down to 55-60 mph I've seen as good as 23.5 mpg on a 475 mile round-trip from Raleigh, NC to Virginia Beach, VA, with around 45 miles of city driving while in VB. By contrast, heavily loaded, towing my 6 X 12' utility trailer, and with vicious headwinds going and coming, and running 65-75 mph most of the way, my last trip to and from VB saw just 13.8 mpg. I don't care to tow the camper much faster than 65-68 mph and most of our local/regional trips with it have been to the NC or TN Blue Ridge or Smoky Mountains, and we see 14.25 to 15.75 mpg on those runs. While towing, she normally holds 6th gear on the upgrades if not too steep, but does prefer 5th on steeper or longer grades. I normally shift to "M" and paddle-shift on hilly terrain because I don't like the way the kickdown works while in "D".
All in all, the F150 has been one of the better trucks I've had over the last 48 years of driving only 4WD pickups, Scouts, Wagoneers, or Suburbans. Only time will tell how durable the little sewing machine motor will be, but she'll turn 120,000 miles on a camper-towing trip to Hot Springs, NC on 5/21 so she's already getting a bit long in the tooth. And, she runs like a scalded cat when the old hot-rodder in me wants her to.