I've owned (leased) the ML for a few months now. I turned in a GL which is a full size SUV.
What I like:
The ML has a great ride and very easy steering. For those who like a tight steering wheel, buy a BMW.
This ML is very easy to drive.
I also upgraded to the Harmon Kardon stereo and it is worth the money - crisp and clear with a nice mid range. The ride of the ML is very comfortable. Again, if you like a sporty ride, look else where. I appreciate the comfortable ride, comfortable seats and quietness in the cabin.
In addition, the quality of the materials in the cabin are what you would expect from Mercedes Benz.
What's not to like:
The exterior styling and price.
Quiet comfortable ride. Mercedes Benz' are very reliable vehicles.
Harmon Kardon stereo. Rear camera is excellent. Improved nav system from prior models. Comfortable seats and overall great cabin design.
Bluetooth support (but they all have it even the inexpensive cars).
You definitely pay a premium for the privilege of owning a Mercedes - you really have to weigh whether its worth the extra dough.
The exterior styling is.... meh.
It looks like a lot of other mid size SUV's - nothing special to look at. Although they improved the nav system its not best-in-class and for the price, it should be - no touch screen and voice command is still not perfected.