On on my second set of Michelins. The first set of LTX M/S was replaced under warranty even though I'd had no problems. The second set lasted around 50,000 miles. The third set is the LTX M/S 2. I've only had them for a couple months but they're doing fine.
I typically carry between 5,000 and 9,000 pounds on my rear axle depending on the use of the truck. When I had the boat the whole rig with TC and boat was around 18,000 pounds. The tires wear good, ride good, and just work really well.
Michelin was one of very few companies to offer a mileage warranty on a truck tire. When the second set didn't make the warranty they told me that Michelin probably wouldn't do anything since my truck was a commercial vehicle. (I have a flat bed on it with tool boxes for my electrical business.)
Overall, I recommend the tires but don't expect to get super great wear if you run heavy all the time like I do.