I am running the LTX MS2 as well. For a highway tire, they are incredible. Compared to the stock Bridgestone's, these are 10x better. They aren't the best for off road because they can still fill up with mud fast, but last year when we got a lot of ice in DFW, Texas these things didn't have any problem coupled with my 4x4. They are also great on wet roads.
I rotate mine every 5,000 miles. I have read around the net and the guy at Discount said that they have seen these tires get over 100,000 miles on them before needing to be replaced.
If you mainly use your car on the road and need a great, long-lasting tire, these are the way to go. I have put 20,000 miles on mine so far, and the tread looks great still.