I had the LTX MS2's put on a few months ago, so probably approaching 10K miles on them. I had the Dunlops until about 55K, then switched to Goodyear Fortera Tripletreads and those went until about 120K (still had some life on them, but wanted something new before winter), and now of course the LTX MS2s.
This obviously goes without saying, but both the Tripletread and LTX MS2 are way better than the Dunlops. The Tripletreads were absolutely amazing in the rain, stuck like glue, and awesome in the snow as well. But they also were significantly noisier in the rain. Very good tread wear too...got more than I figured I would. They also knocked my mileage down by 1-1.5 mpg until they started to wear a bit. The LTX MS2s seem to stick very well in the rain too, but without the added noise. Additionally, I have not noticed a significant drop in mileage. I have not had the chance to evaluate them in the snow yet. In normal driving, I find it hard to tell the difference between the two as far as ride comfort and noise...I would have had no problem buying the Tripletreads again, but just wanted a change.
Ultimately, I was able to find a killer deal on the LTX MS2s installed through Sears ($730 installed inc tax and $70 Michelin rebate), so I went with them and I have been very pleased so far. For those weighing the two, you can't go wrong with either one.