We tow a 2012 25FB Flying Cloud with a 2012 Ford F150 FX2 SuperCrew with an EcoBoost and the Max Trailer towing package. We are happy with the performance while towing; the truck has always had plenty of power. Even towing in the mountains out West, the truck had the power to pull as fast as I wanted to go.
That said, a few things you should consider:
1) We always go 65mph or less, so going up a mountain at 80mph isn't anything we cared to do
2) The MaxPayload is (was?) only available on the long bed. If a long bed would have fit in our garage, I probably would have gotten that because ...
3) The thing you will run up against is the not the max trailer weight (which is a function of the Gross Combined Vehicle Weight Rating - GCWR). You probably *WILL* get close to the Gross Vehicle Weight Rating - GVWR and/or the Gross Rear Axle Weight Rating - GRAWR.
I did a *bunch* of research, and with a weight distribution hitch, the tongue weight of the trailer, 2 adults, 2 100-pound dogs, the truck accessories (running boards, tonneau cover), and our camping stuff, I think we come to within 500-700 pounds of the GVWR and/or the GRAWR. We have to be mindful of what we put in the truck bed. However, we have always been able to take what we need.
If you went with a 250, you wouldn't have the payload issue.
Here are some posts and threads with details
Thread with me asking about a F150 towing a 25FB
Details and links to Ford 2012 specs, towing guide, and payload workbook
Hope that helps.