Going to have to agree and chime in as well...
I haven't been plagued with as many problems as some with the ML, and the issues I have with my W124 have too, been mostly electrical issues. Fortunately, it was a common MB platform and parts are relatively inexpensive.
As much as I drool over the R230, I find the R129 complicated enough, and woe to the R230 individual that eventually has to repair the "active" suspension. I believe someone on the forum attested to a bill of a few thousand dollars per wheel!