Although I am also suspect of the Jiffy Lube type places, doing an oil change is not rocket science. The only concern I have about these places applies to ANY car. They are known to strip oil plug threads. Finding the oil fill hole on an MB is not difficult, even for the IQ of 70 type people in these places.
The IQ of 70, however, is not always adequate for replacing a drain plug without stripping the threads.
My BIGGEST CONCERN is their recommendation of Dino 5W30. UNLESS YOU LIVE IN ALASKA, DON'T USE 5W30. It is too light for non Arctic climate. BMW put out a notice recently that they were seeing accelerated engine wear with this oil. Synthetic 5W40 or 5W50 is okay, but lay off 5W30 Dino. 20W40 or so would be much better.