I still propose that it may be difficult to come to any conclusive declaration as to which version of which, by now, 30 year old lens is "better". Even if you just decide to concentrate on say, sharpness- by now so many years have gone by and unless whomever is doing the test has owned all versions since new and stored them in exactly the same conditions, there's bound to be some difference between lens # 998700 and #1000002 if they were stored in different climates and one owner was attentive and one just tossed it in a drawer for 15 years and forgot about it. And what about sample vairiation with regard to haze, dust, or which anal retentive gear fondler cleaned a front element too aggressively for the past 15 years and maybe wore off 80% of the coatings? It would be impossible to tell. Adding to the mix whether or not one lens or the other had had a CLA 1, 5, or 10 years in the past ( and just who did that CLA? Was it John Hermanson- a top notch Olympus tech, or someone's drunk Uncle Bill? ) could further muck up any comparison so that you maybe couldn't come up with a "definitive" rating or ranking. (IMO)
You certainly may be able to say that this 50/1.4 is sharper than that 50/1.2, but I don't think that after this much time using only one example of each lens, with storage and condition variation you could definitively say that all 50/1.4s are this much sharper than all 50/1.2s, etc.
I take all ratings with a grain of salt and just try to get a very clean example of a particular lens that I'm interested in and try it out myself to see if it gives me what I'm looking for. Heck, what lens works for me in portraiture may not work for you in macro or shooting stage performances. If I hate it, it just goes back on fleabay.
