I think I'll trust Mercedes before I trust the claims of Zerex or any other company.
I was just reading a loooong article in the Star Magazine about the unique properties of MB coolant and why you should trust nothing else.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".