After reading all the comments on this thread, I'm beginning to think that people must say to themselves "There goes a Mercedes owner, snicker, snicker!" I myself don't quite qualify, since my 1982 300D has had an engine/transmission transplant, which is a 1991 Astrovan V6 with T700R4 transmission. Since doing the conversion almost two years ago, I have had NO problems AT ALL with the drivetrain, and the car has much more power than it used to, still gets 28 mpg on the freeway at 75-85 MPH with the AC running, and around 20 mpg around town. The things I HAVE had trouble with are: Window motors not running due to bad switches, required switch replacement, Tach amplifier quits every so often and I have to replug the connector, Driver's door stop had to be replaced (Don't understand why they put the tach amp in the service connector to begin with!), rear window has a slight leak. I can put up with those nitty items, but I could not handle a power train problem, I need to use the car! I made two trips from the Portland, OR area to Vancouver, BC this last summer, and the car is a dream to drive on the freeway, will keep up with the best of the machines, and I always have a smile on my face when I park it, because it is in my opinion a "sleeper", an innocent looking car that does much more than expected. By the way, the conversion cost me under a thousand, and I haven't had to spend any money on the drive train since except for front brake pads. My wife has a 1994 Ford Taurus, which I must say I would have to compare your transmission challenged Mercedes vehicles to... I'm sure if there were more Mercedes on the highway and they were made in the US there would be a public outcry over many of the MB woes, and maybe a recall or two to fix some of the obvious design problems you are talking about. Our previous Mercedes was a '75 280, which had a herky-jerky but dead reliable transmission and engine.
Sorry to be so opinionated, but I don't understand why you insist on flogging a dead horse!
'82 300D/4.3L V6
'94 Taurus (Wife's car, iffy transmission like a benz)
'88 Astrovan (solid as a rock!)
'77 Jag XJ6 (It's going to get a 4.3 one of these days also)
'77 280Z (Also solid as a rock)
'85 GMC S15 (Great little pickup)
'65 Clark Cortez (78 Caddie engine/transaxle transplant)