Which is the most maligned camera? The polls show that it is the M5. Which is the most advanced ergonomically and easiest to use? Well, again that argument could be for the M5.
I purchased my first Leica camera in 1974 when I decided to get rid of the Nikon F's and that I no longer wished to follow photojournalism as a career. I have owned the Leica CL, M3, M2 (several times), M4, M4-2, M4P, M6, M6TTL along with the M9 and now MP240. I had never shot with an M5 until two years ago when I purchased one from Sherry just for the hell of it. It is now my favorite film M followed closely by the M2 and M4.
Yes, it does not have the classic lines of an M film camera but neither does a Hasselblad or Nikon F. The M5 was in development for over a decade and would have had the same effect on rangefinders as the M3 did on screw mount development. Unfortunatly, it was introduced about the same time that SLR's were taking over 35mm photography which consigned Leica cameras to a niche which is where they are still located today.