tires for my Duelley

Well here is the story on tires on our 2003 Dodge dually, quad cab, 2wd. Came new with Goodyear Wrangler SRA tires. Got 67,000 miles out of them, no problem. So on the next set I went with the same tire, Goodyear Wrangler SRA and struggled to get 45,000 miles. Fast forward to spring of 2010. Was in the San Antonio, TX. area went tire hunting. Was seriously thinking of going Michelin. Well no matter where I went for prices whether it was a corporate outfit, a little tire shop, etc. I could tell you the price before I even walked in the door. At that time Michelin was bringing out the MS2 a replacement for LTX. LTX was $232.00, MS2 was $242.00. Price fixed!Couldn't find a Yokohama Geolander to get a price. So, I saw more Firestone tire shops in the S.A. area then I've seen anywhere in years. Went in one just on the outskirts of the downtown area and asked what they had to offer, knowing it was going to be Firestone TransForce HT or AT. He asked how many I wanted as he couldn't see what I came in because the truck was parked across the street while my wife went in a sewing shop. He printed out a pricing sheet, I took it back to the RV park where we were staying at and scoped it out. Came out to $155.00 a tire but the final price didn't reflect what 6 tires would be. Called the shop and yes that is correct as you are buying 6, you get one free. Went in the next day and had them mounted. I figured at that price if the mileage where they wear out isn't all that great I'm still in fairly good shape price wise. So today I have 40,000 miles on those Firestones and will be very fortunate to get 43,000 out of them. All 3 sets just wore out, no uneven wearing etc. As far as the use of all 3 sets, the amount of trailering, the amount of running empty, and the roads used on are all basically the same from year to year. If Michelin is a 70,000 mile tire I would go for them if I would get that mileage but if I don't what is the Michelin Man going to do for me? Now, I have nothing against Michelin as I am on the 2nd set of their XPS Ribs on our fiver as I have had excellent service. Also I never had a problem with any of the above 3 sets of tires, they just plumb wore out. So as far as I'm concerned, it is a******shoot with whatever you go with. And I refuse to say a tire is really good if I've run it a just couple thousand miles up and down the slab.