May I present a slightly deviating view? In my time, I have owned a Leica IIIa (2 examples), IIIb, IIIc, IIIf (two examples) and M3 (two examples), not to mention a British Reid III and two Voigtländers which I still have.
Originally Posted by janké
What made me give up on Leica was this - I acquired an M3 in good working order, but as it had never been serviced, decided to get this done. Leica UK charged me £400 to replace shutter curtains and carry out a general service, when I received the camera back it seized after 3 exposures. It went back, on its return the shutter was "tapering". It went back again, on its return, the shutter was not lightproof when changing lenses (even in body shadow). I finally got this cured by an independent repairman, was by then feeling very negative about Leica, and in the end decided I did not like the modern iterations of the Summicron lenses (very contrasty, great if you want your slides to look snappy on the screen, murder for b+w work). I actually preferred the 43 mm f1.9 special edition lens on my Pentax, although I did consider spending a lot more money to find good examples of 1960s Summicrons, which I personally prefer.
Through numerous conversations with acquaintances and friends in the trade here in the UK, I learned that I was not the only one to fall foul of this service department. Leicas are in any case hard to service, unlike modern products which are modular and where the offending module is simply removed and replaced. There may be some appeal in using a "good old" camera, but many would rather have a "good new" one.