I'm looking at replacing my ML tires soon, but I will probably stay with the OEM Grabbers for the reason you stated...long life!
I have three MBs to deal with when it comes to tires. Just replaced the second set on the W124 this summer, and the SL looks to need a set by next year as well. This would be a very expensive budget buster if I had to shod each one with sticky sports performance tires...so long life is VERY important to me.
I've been satisfied with the Grabbers, and my use of the ML is primarily for highway travel and weekend jaunts to soccer games and retail hunting and gathering.
I don't ask much of the ML, no shaloms, rock climbing trails, or snowy treks through Donners Pass or anything, just easy paved road cruising.
