You would be AMAZED at what the ML can do. The ETS / Low Range combination needs to be experienced to be believed. It also takes some training. In any low traction situation - put the car in N, brake on. put car in Low Range. Wait till it activates. When it does - put car in "1", take foot off brake and do not apply again till you are completly out of the woods. Keep a constant speed - not too fast, just try to maintain a slow steady pace.
I was able to not only get a test RIDE on the offroad track in Vance, but actually DROVE the entire thing myself - it was a no-no at the time, but my driver was very cool about it. I have it all on video. I don't know if this was the norm afterward - someone can back me up if they got the same chance.
-Joe