I'm almost a believer.
I've always thought the "problem" with Marathons was caused by underinflation or driving too fast. This happened to me yesterday at 60mpg after two hours of highway driving. We had grandkids in the back seat watching DVDs, and I thought the loud screeching noise was from a movie. A big truck honked at us, and I looked in the right rearview mirror and saw the fender damage.
(sorry for the edit but forgot this)... I haven't looked closely yet, but I did notice tire debris inside the cabin at both ends of the LR slideout. I'm wary of extending the slide in case it gets stuck "out." Anyone else have a similar debris-inside-the-cabin experience?