An early M4-2 (w/in the first 500 of 1977 year serial#s) with the uncommon Leitz "Wetzlar" on the top plate. A landmark camera for me as it is the first "M" that I performed my own CLA. Having owned (but never opened) M2, M3, M4, M5 and M6, I don't believe the M4-2s any less quality in practical use. Maybe a tiny bit less in the finishing details, example, the actual film frame is not machined as perfectly as the other Ms--I mean the corners are slightly rough by less than a hair's width--but that's pretty nitpicky. I'll give it 6 months and get back to you if anything major arises 🙂
I think the M4-2 gets a bad rap in part because it is noticeably lighter than the other the 'traditional' Ms. 524g without film. That's 86g lighter than the current MP; 100g less than the M5 or M7; 60g less than the M2/M3/M4. That, and the clean, non-flare VF, are big pluses for me.