Great question with many diverse comments. We all have different experiences; good and bad ... Here's mine:
Bought the 2008 coach on a Freightliner chassis with Goodyear 670RV all around. Had each wheel weighed and consulted the Goodyear weight/pressure charts and kept them appropriately inflated. Regardless of manufacturer, this is the absolute best practice. BTW, we full time and have put 30K+ miles on the coach in two years.
Just this past June, we had a inside rear dual go flat (good thing I had pressure monitors, another best practice) and it appears the tread simply separated from the casing; a Goodyear defective tire. Also, I have never been completely satisfied with the overall handling of the coach.
I just replaced the steering axle Goodyear 670RV's with Michelin XZA2 Energy's. I cannot believe the positive difference in ride and handling. I am now a Michelin believer. Still running the Goodyear on the drive axle duals but when ready to replace those, I will go Michelin.
So, it may not make too much difference which manufacturer you choose. What is important is to have each wheel weighed, adjust pressure appropriately, strongly recommend pressure monitors, keep the front end in tip/top shape, drive defensively and enjoy the ride. Both companies enjoy great reputations.
Attached is the Goodyear with tread separation.