So far so good for my 722.6, 2000 C280 with about 96m.

I had a new tranny put in my 1991 300CE at Sun Valley.

He said the newer trannies coming in that did not have fluid changes, i.e. lifetime fill 722.6s, were coming in thrashed. He said the innards looked like they had been sandblasted. He expected even worse from the latest trannies because electronic parts sit submerged in the hot oil. Could be just counter banter.

He said just change fluid regularly and no need for the fancy stuff.