As others said, get the OEM stuff from the dealer, its orange I believe, and the price difference is negligable.
Though personally I don't see why one brand would make much difference over another, you might as well just go for the OEM stuff as long as you are looking for the best, MB will tell you theirs is the best, so you might as well trust in those who built the car.
I havent even checked to see what my mech used, but I don't care, the car runs much cooler than before in hotter weather with AC on max Cold.
So why mess with something thats workin.
I'll check it, if its the "good" stuff, I'll let you guys know.