Haven't keep up with the used M5s available, but many of the ones I've seen are either well used of not at all [or for a long time], the two case ends of Leicas in most need of a good CLA (Leica need to be used to stay in good working condition). If you have doubts about the M5 durability ask Sherry Krauter or Don Goldberg about them. I know Sherry will tell you the M5 along with the M3 are the 2 best Leicas ever made.
I must be an odd photographer; I like the M5, 1st version 50 Summilux, 1st version 90 Summicron and for good measure the 4th version Summicron, and have an Apple Macbook Pro, even have a Porsche Boxster S (not a 'real'' Porsche some will say but it was a gift and is a real fun roadster to drive, and not a 70s Corvette 😱 eech.
Was out last night with the M5 and my new MP, although there is something to be said to the diodes in low light readability (much like the Xmas tree lights we have up), the M5 with its semi-spot meter was able to take the reading the MP could only hope for, and without lighting up the [viewfinder] night (hint: an index finger over the lower part of the finder makes the needles AND shutter speed more visible when needed).