I dunno, we only got around 17-19 with our old 2013 EcoBoost... 21 on one road trip when we had a strong tailwind :) So, not that great, and it wasn't very good at hauling our old toyhauler (not the current one we have now). To me, the trade off to have a truck that was better at hauling was worth the gas mileage trade off. We get 14-15 in our DRW now when not pulling the trailer.
Now, my daily driver is a 2016 Explorer Sport with the Ecoboost and I'm lucky to get 22 combined city/highway. I got it up to 24 when doing a road trip with long stretches of highway. So not exactly a gas hog, but not what I'd consider "great" gas mileage either.