I'm not actually convinced that the W123 is any less reliable than "modern" cars owned by friends and cow-orkers. And what it does need can generally be done by myself in less time than it takes to take it to a mechanic, drop it off, come back, pick it up, etc.

Comfort is fine, A/C would be "nice to have", but with the way this summer is going (heat for a day around Memorial Day and a weeklong-heat wave, otherwise cool and dry; sitting with an open office window no A/C right now and I'm very comfortable), I'm not convinced it's really been needed.

If I replace it, I'm probably going less comfy and less reliable -- Fiat 500 here I come. (Probably on a lease, since I don't trust the quality enough to want to own one in 5-10 years).