Well, after being with out an RV for the past nine years I broke down and bought another 5R. It had ST tires on it, that probably hadn't been run 2500 miles on the RV sat since 07.
I got on here and spent the last two months reviewing RV tires. I was almost ready to put on the tow max tires, but at the last minute today, I broke down and bought the Michelin XP ribs. With a 14 ply they are rated at 3700, the same as the ST's were. The cost was out of sight at $1,600 for five, but hopefully these will be the last tires I ever have to buy for it. Just hope I have no blow outs.