Well, the Lynx is not that big. It has a very nice viewfinder. Focus is extra smooth (smoothest of all my cameras). It has a finger rest under the lens to focus faster. The rangefinder is super bright. Nice camera.
As for the Argus, it was indeed very popular. There was even an update service for their owners! As soon as a new model came out, you could send your old camera for a feature upgrade. Techs would dismantle it and put in new parts for cheap. The only way to tell which model is which is to look at the number of available shutter speeds...
They did make millions of them. The rangefinder coupling gear is very important as without it the rangefinder is useless. The rangefinder is also separate from the finder. Lenses are removable (but the process is so clumsy... even worse than Leica Screw Mount!). On mine, focus is extra stiff... I tried oiling the outside parts to no avail. I would have to open it to really clean the inside. Also, rangefinder is none too bright and the framing finder has a lot of glare (and they're oh so small!)...
Also, stay away from the Yashica 35MF... had one and it's far from even decent!
Back to the Lynx, here's a picture of mine, A yashica Lynx-5000 with a 45mm f/1.8 lens