OK, one of my obsessions so excuse me if I ramble on. First, the design is very American. Chunky. Definitely Chevrolet, not Porsche. Unlike most cameras, the Medalist doesn't seem to 'fit the hand' naturally like a Leica or most any other camera designed to be hand-held. Once you get a feel for it, though, it actually sits in the hand well. Although the shutter release is long and doesn't have the precision of a Leica or Rollei or such, so doing action/street work will take some serious practice to get the shutter release point and timing to come smoothly. The separate rangefinder works fine all in all. The position of its window under the viewfinder works well, a simple glance downward. The rangefinder image is pretty magnified which leads to precision but can also make it confusing when you first glance into it to orient as to what exactly you are seeing.
Mechanically it is, well, unique? Rube Goldberg was obviously a consultant, or an inspiration. At the same time, it is a very 'raw' mechanism, designed to be worked on by soldiers, not a huge amount of finesse or precision but very solid and works smoothly. Each 'system' stands on its own and can be figured out with a little study. There are good manuals available for doing repairs. Most good camera repair person could probably suss out the workings and do good work on it.
The lens is wonderful. It's why I even mess with the whole thing. I have used it on a tripod most of the time. Recently I started shooting hand-held more, and am enjoying it, but a Leica it ain't.
I recently finished my first version of converting a Medalist to 120 film. The clunky design leaves lots of room for machining and modifiying. The first test run by another photographer worked well. Soon I'll know enough to be able to offer work and conversions on the Medalists. If anyone is interested in being a tester of a 120 converted camera, drop me a note.
Having bought a few, the major issue is a balky shutter. The Supermatics have not aged well and will usually need a good stripdown and cleaning. About half of the rangefinders I have seen need adjustments. Watch the front viewfinder window- these seem to be cracked or chipped on about a quarter of them. As with any old camera, dirt and grease can make basics difficult- focus tubes, shutter button, sync of shutter release and wind system, etc.