There is certainly a bunch of Leica koolaid floating around in this thread.
For the record, in my experience Leica cameras are certainly wonderful pieces of equipment, but they will also require regular service and adjustment. Don't forget, the M2, M3 and M4 cameras were all built at least 30 years ago, some of them as long ago as 50 or more years. They are very old.
The Voigtlander Cosina cameras are much, much newer. They have meters. Film is loaded in a more normal manner. They are very reliable and they cost far less. Are they as smooth in operation as a Leica? No. Does that make them less reliable? Who knows! They have not been around that long. Will they need adjustment at some point? Sure, most cameras do. Especially rangefinders. Nobody makes a rangefinder that will not eventually go out of adjustment, not even the sainted Leica. (See below.) Will they need repair more often? Who knows. There is anecdotal stories of Voigtlander Cosina (VC) camera needing repair in 12 to 18 months. I can tell you the same stories about Leicas. In fact, if you were to go on my experience I have never had to send a single one of my three VC cameras in for service, while having to have several Leicas repaired in the same time period. Does that mean anything important? Of course not. Your own experiences will almost certainly be completely different than my own.
Leica makes great cameras and I love working with them.
Voigtlander Cosina makes great cameras and I love working with them as well.
If you find a good Leica, buy it. You will probably enjoy it. If you find a good Bessa R2 or R3 that you like, buy it. You will enjoy it as well.
And if you are interested, Zeiss Ikon also made a terrific, modern M-mount rangefinder that is a wonderful camera.
EDIT - The rangefinder in the Contax II is the only rangefinder built that I am aware of that will probably last for a very long time without adjustment. But by this time the glue holding the prisms together is about ready to start to deteriorate and fail, if it hasn't already. When that happens the secondary image disappears.