The M112 18-valve V6 is not really considered the pinnacle of M-B gas engine tech; and the interior is certainly not what lots of people expected from a Benz, certainly if you had just stepped out of a '94 500E W124. The body when prepped right is comfortable and sturdy tho. I'm sure it was heavily used in much of the world as a taxi, like a Camry (except with an M-B turbodiesel).
A good endorsement of it is that the Chrysler LX cars, which shared more than a few W210/211 bits, have been on sale with only cosmetic updates since 2005...
I had the OM606A, which was very well-regarded overall and mine went to 211K miles with no drama and the occasional glow plug was the only unscheduled maintenance I experienced in almost a decade of my ownership.
A good endorsement of it is that the Chrysler LX cars, which shared more than a few W210/211 bits, have been on sale with only cosmetic updates since 2005...