Jono, I learned my statistic lesson with Leica M lenses
I can tell you with some certainty that I have or have had:
1 CV 15 (perfect, still got it)
1 WATE (perfect performer but not the right form factor, sold it)
1 24 Elmarit (not perfect but pretty good. Sold it.)
1 28 Cron (perfect, still got it)
1 35 Lux (chronic focus shift, returned)
2 35 Cron (Chronic focus shift, dumped)
2 CV 35mm F2.5 (one perfect, still got it, one returned)
1 MATE (bought from Jono, perfect but boring, sold it)
1 Noctilux (second hand, got it coded, it's perfect, still got it)
1 50 lux (perfect, still got it)
1 75 Cron (perfect but I never used it, sold)
1 90 Cron (perfect but too chunky, sold it)
1 90 Macro Elmar (perfect, still have it)
So that's 15 lenses and only 4 had to go because they didn't focus properly.
Which is only a 27% failure rate. I can live with that!
:ROTFL: