Our 2015 F250 is the same truck as you're describing with the exception of ours being a Lariat. We live in Tampa. Locally my mileage is always 14-15 Hwy/12-13 City. Here it's all about traffic flow.
Myself, I've owned both Gas and Diesel trucks. They each have there place. Mine is my daily driver, I start it and stop it all day. Diesel trucks don't like that.
As for Towing, we own an Arctic Fox Travel Trailer. I've never weighed it, but I'll guess it's less than 9000lbs. Mileage, 10-11 mpg between 60/65 mph. I'm not in much of a hurry to get anywhere soon. We love the truck ...