Glad to hear that they are on the way to solving your car's problems.
As to the recent post by Larry Bible, I agree. David's been a significant contributor to our little world here, and has shown a maturity and enthusiasm beyond his years.
As to the C-Class, I don't understand beating it up. The W202 version was the model ranked as the most reliable and trouble free of the Mercedes line-up during it's tenure. Even outfits like Consumer Reports rated it very high.
Having owned mine for only five years, I can't comment on the "decade" plus potential, but so far it's a truly "perfect" car. At 122,000 kilometers (~76,000 miles) it's been trouble free and wonderfully reliable.
Mercedes can't sell a 240D today. Not a chance. It would be expensive and other than a core group of MB nuts, wouldn't sell worth a darn. No airbags? No ABS? No traction control? Lousy stereo? Tepid AC? No passing power?
Mercedes faces much stiffer competition than ever before. Automotive reliability has increased dramatically in the last 15 years, and even a Lexus LS430 isn't really any more reliable (maybe less?) than a Toyota Corolla. So how to differentiate? Features? Seems to be the way companies are going right now.
Mercedes would be laughed at if they re-introduced the W126. 238hp from 5.6L? Four speed automatic? No multi-zone ACC? Two airbags? And so on...
While the W126 560SEL suits YOU better, it's a matter of taste. I have seat time in a W126 LWB, and find it a VERY nice car to drive, but it's not my cup of tea. The car is plain too big and ponderous for me. The fuel economy/performance ratio is terrible, especially compared to newer designs. It's not for everyone.
It would be impossible to determine which, a 1991 SEL or 2000 C-Class that would perform tops in JD Power. Your question sounds rhetorical, assuming the W126 would win. Why? I know many C-Class owners, some with astronomical mileage, that have been more than happy with their cars.
And btw, if you're wondering how your original comment comes across, it makes it sound as if anyone that chooses a C-Class is somehow dumb.
1998 C230 "Black Betty"