I am happy with the 500 c/m I bought a couple of years ago. Previously I borrowed one that my wife sort of shares with another poster on this list. It is prone to jamming as the camera needs work. It is a matter of carrying a stubby screwdriver in the camera bag. I did not like the 50mm and bought a 60 CF as my wide angle lens whereas my wife has the 50 on most of the time.
It seems to me that the 500 c/m is not only dependable but is noticeably less expensive than the newer models. Lots of us are using them with no problem,there is a reason that I can not go into here to not repair the one that jams but it most likely is a moderate cost to have it serviced. Go for it as there are really great cameras.