Big thing with ecoboost is you will get the good fuel economy if you keep it stock as is. I bought mine with 18" wheels and some small tires. I put a 2" level on it and have 35". It took a little trimming but do t scrub unless I hit something hard turning. All in all I'm happy with the truck I have coil overs in the rear with bags too.
I have Lincoln MKT with a 3.5 eco boost. Sum bitch moves, and gets 25-26 on the highway. It's a blast to drive. It's got 103,000 miles now. I have seriously considered getting an f150 after owning this.
I have a 2015 4x4 with the small 2.7 ecoboost. Gets 13mpg pulling my buggy and trailer (4000lbs) and 22 if I baby it empty 20 if I drive it normal. Don't have any dyno numbers or track times but it will get up and go pretty good.