Up pikes peak with the ML500.
Just got back from my road trip. 4300 miles, no problems at all out of the ML. I drove it up and back down pikes peak, which was a lot of fun. It had no trouble at all, and afterwards I drove it 300 more miles that evening. The Navigation system was either hot or cold. It would find me some things I couldn't see on a map, but threw in enough wrong turns, back tracking and non existant places to make me sick. I will definately let the boys at MB know about it. In one case the system wouldn't navigate to a road which was labeled on the map. Really caused a lot of frustration. The road was shown and named on the screen, but you couldn't input it as a destination!
The Valentine one radar detector was very useful, and I tried to maintain 80MPH throughout most of the trip. It didn't use any oil or anything either.
I found that only 91 octane and in one case 90 octane was available in many parts of the country, and 93 octane gives it .6 to 1.5 MPG better economy.