I've heard the rational on MB coolant before..
MB buffers their solution. Go buy some ph strips and check MB coolant diluted 50/50... it's pretty close to 7.
If you go get your green stuff, it will be really basic. Then as it ages, it becomes really acidic. That's what is suppose to be horrible on the rubber and plastic parts.
My experience recently attaining a dealer serviced 1986 car. It had a bad radiator just like any MB which ran the green crap. So, I'm not sure it matters as much with the radiator,but I've seen 250,000 miles 18 year old hoses which look much better than US stuff.
Flushing... just do a few rinses with water. MB suggests a degreaser or citric acid as flushing agents.
Summary- I'm not sure you can go wrong with the MB stuff. THe buffering(keeping it ph neutral throughout the life of the coolant) is a good thing... even if it doesn't save your radiator.
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD