My experience is the following.

if your going to have your Mercedes aligned go to a dealer or a Mercedes SPECIALIST - and be sure the independent is not some fly by night operation but has the specific tools needed to do a Mercedes and has experience.

Prime yourself on Mercedes Benz style weights, they look good and work very well.
I've seen alignment specialist who say all they do are alignments and they can do Mercedes Benz and their computer has Mercedes Benz specs installed. I've seen them screw things up BAD.