Do you have or did you used to have a 300SD, and did you ever go to the MB club parts scramble at AAA Small Car World and pull a steering box?
If I were close enough to Donnie or Steve, I would most definitely put my car in their hands for alignment. Fact is I live 1,000 miles from Donnie and a good bit further from Steve. I have no front end person that I KNOW will do everything correctly and not because it's an MB. As a result, I make do since my biggest concern is tire wear and I have managed to keep the toe aligned with my country boy method.
I too agree that MB alignment is not magic, but it needs to be done correctly. If there is a need for anything beyond setting the toe, it will have to be done by someone with experience and savvy or most likely it won't get done correctly.
Have a great day,