Lots of Independent shops use platinum plugs, they are often used for an engine that is starting to burn oil because they burn a little hotter. I have never heard of a problem with Bosch platinum plugs and do not remember ever seeing any technical info from Mercedes-Benz to the contrary (20+ years at dealers).
A properly running Mercedes will run just fine with the normal Bosch plugs.
How about a discussion about Spark plug replacement intervals?? Some change them at 15,000 miles or at 30,000 or more. Assuming we are talking only about fuel injection, would the different fuel injection systems (CIS, CIS-E, LH, HFM, or ME2?) require less frequent changes??