The 140 V12 always looks like a "good deal" (Gee, I can get into the S600 sooooo cheap!) Don't do it! There's a reason they are cheap to buy, because it's ready to eat you alive!
The jury is still out on the 220 S Class V12, time will tell. Even the 140's did OK while they were still under warranty.
I just can't help thinking that it can't get a whole lot worse. But in 5 years we may all laugh at that prediction.
King of the Road, Hmmmmm. As a replacement for a 260E?
Maybe a 560SEL, latest model you could get was what a 1991? Those are pretty nice. If you reallllllly want the glory wagon, you could maybe try for a S500 (140) instead of the V12. The engine is a lot more dependable, only main concerns would be the AC evap and the steering gear box, both cost about the same to replace (some people will try resealing the steering gear box, but replacement with an MB reman ((if available)) is a more dependable repair). If you wanted to get a 210 chassis E Class (good choice), as far as a glory wagon, you could try for an E55 AMG, but a couple other good choices would be a 97 E420 (210 chassis with a 119 motor--awesome and unappreciated car), or an E430 is also a fun ride, maybe you can find an E420 or E430 Sport version.