I suspect that it's a bit of a myth that the 1.1M versions are optically superior to any other verions although I haven't had a chance to test that. There will always be sample variations too so I doubt it can ever be either proven or disproven. Even if there where manufacturing changes in the later serial number versions it doesn't always translate to optical differences. I suspect that any of the later (multi coated) versions will perform about equally. I have a fairly late 862xxx serial # lens which I find to be excellent. It's a '1 owner', I bought it new in the mid 80's.
I have tested them. I had one with a 600,000 range serial and I have two of the 1,1 million ones. They're night and day. The high serial ones are identical in performance. Sharper wide open and far better bokeh too. No contest, given there seems to be no price difference today, you'd be a fool to buy an older one.
Fine Art Photography of Indiana and other places no one else photographs.
Well my mate loaned me his OM-1/50 1.4 a week ago and now I'm thinking I'll need to check the serial and see how it stacks up.
Might stick it on the 5D and do some tests.
Tests done with a digital sensor may not accurately reflect results on film - just as test results can vary if different films are used for the testing.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
Is this a limbo contest? After crushing my first one with the Carmel Mission front door I felt justified spending more than necessary to replace it. So I went to a camera shop in Santa Cruz and found and bought #134962. I don't have a Geiger counter to check it but it is kind of yellow.