I'm sure Tim will chime in with his impressions, but I'll offer up my quick review of the 2.7 EcoBoost in my 2015 F150.
Been driving the truck for about 10 months, and got a Hawk camper in May. So far I've been very happy with the engine. With no camper or load, it's pretty peppy while sipping gas at about 22 to 23 mpg for combined town and interstate driving. It will jump when I push it, and I've never felt any lag due to turbo spin-up.
This past weekend I had the camper in the southwest Virginia mountains and got 17 mpg with a fully loaded camper. I didn't drive aggressively but felt like I had plenty of power to spare going up the hills.
There have been a lot of reports on the F150 forums of shuddering during acceleration due to ingestion of water that condenses in the intercooler. Apparently this tends to happen in humid environments. It's pretty humid where I live, but I haven't experienced it yet.
While I'm impressed and happy now, it'll be interesting to see how reliability shakes out long term. Also, I'll be curious to see how durable the epoxy used to fasten the aluminum body parts will be.
- Rusty