Fantastic post, Remsky, thank you very much. I had a feeling that much of this is the case. I did forget about the material change though, somehow. This still seems to (mostly) support my very limited experience. I do, generally, believe in the old adage, "They don't make them like they used to." I'm a huge fan of older things for their craftsmanship. However, how much difference can a minimally iterative design have throughout its production life?
It certainly is not inconceivable that wear, tooling changes, nostalgia, and wishful thinking can cause people to give greater emphasis to certain data points over others. It would certainly be interesting to be able to compare as many varying batches of NOS MX switches as possible against each other to put this one to rest one way or another.
I should add that I have also briefly tried an old Cherry MX Black Wyse board that didn't feel significantly better or worse than any of the others either, but I only had moments to play with it at the time.