I got the Michelins at Costco and they could not properly balance them. They wrote on the receipt something cryptic about balancing and luckily I looked at it in the cab before driving away. I went back in and asked them about it and they said they could not balance the tires because they were too big for their machine. Sheesh. They had also severely underinflated the inner duallys even though I told them to make sure the pressures were set properly PLEASE. Ended up taking them to a real tire store that deals with a lot of trucks (Bruce's Tire).
The Michelin's are great now that they are mounted properly, but time will tell on the cracking. I like the idea of going 70K on a tire, but I doubt that will happen as I don't drive it enough.