All I can say is, I've had more than one item go "thump" up against the back of the cab, and pretty much every time I get a pallet of mulch or anything at Home Depot the guy driving the forklift bangs the corners of the skid into my wheel wells. I've also had to drag heavy steel items across the bed with a tooth filling screech. Ever see what a 5 gallon bucket of scrap mined from the berm at a shooting range looks like?
Seems like any one of those could put a serious gouge or crease in that aluminium.
I got rear ended once and my bumper put two 3" scrapes in the fender. Just barely creased it. They came right out. Would those have been tears?
I like my 2013 F-150 more and more. But if I'm going to upgrade, better do it before they "improve" the Super Duty