I am implying that an M6 from 1987 say, in mint cosmetic, may still need a CLA when compared to an M6 TTL from 1998. 11 years is a surprisingly long time for a product to stay in tip top shape without adjustments. This is just from an age perspective. I would expect an M6 to be in better condition, on average, than an M3 due to the age differences, so why can't the same be said for the non-TTL and TTL?