Just checking back into this thread.
From my own experiences, my W126 is about as reliable as one could hope for.
They have a lot of room under the hood to do work, and the diesels have much simpler engine electronics.
My 1984 300SD I think of as a faithful wife.
My 1991 300TE is like a sexy, responsive girlfriend with (shopping and other) addictions. She seems to miss my mechanic if they haven't seen each other in a couple of months.
Granted that I have a gas wagon, but a lot of the problems I've experienced are endemic to the W124 body... let's see, OVP relay, exhaust, brakes, voltage regulator, monovalve, frozen ignition tumbler, cranky vacuum door locks, leaky washer fluid tank, cooling system cascade failures (the latter admittedly related to M103 head gasket failure).
Now she's gotten very cranky starting and is dripping something on my driveway. I'm envisioning another trip to my mechanic to troubleshoot both problems.
My wife is noticing the problems, and suggested I sell the W124 and keep the SD.
W124 problems seem to cost more than W126 problems, for both parts and labor.
I told her that my SD is akin to my wife, and the TE is my girlfriend. This way I have no time (or money
) for a warm-blooded human girlfriend... after telling her this she dropped the subject ...
Maybe you should bring your SDL to my house and we can trade my SD for your velour SDL... and I can sell my gas wagon to pay for the repairs to the SDL and buy diesel fuel for the next 10 years... but then I might end up with a human girlfriend, no wife, no home, and no money ... never mind