If you like the look of the W124 then you can't go wrong with the 500E. It has a muscular look with all the right curves, unbelievable power, great handling, superb build quality and every option you could need. Parts are readily available from any dealership and other than the tight engine bay it isn't difficult to work on.
If you haven't had a chance you should take the car for a test drive and determine if you like it. You'll know if you do or don't.
500's are getting very rare in good condition and eventually they will be as scarce as the 6.9 but if your buying the car as an investment don't waste your time, it's too early and the used car market is very soft.
Let me know if you have any specific questions about the car, I would be happy to answer them.