Performances: Good for TMB Original. Bad for clones.
Am I correct?
Not quite that simple. To an extent you have suplied part of the answer: Why the Series 2 if the original Series 1 were good?
Should have taken a copy, if it were possible then, but there were about 7 improvemnets made to the Series 1's to produce the Series 2's. Nothing extreme but the lens edges were blackened, also an internal seperating ring was a nice shiny chrome plated item - that went for a better matt black item. Maybe better AR coatings, better rubber eyecups.
I wanted the originals Mk1's, many years ago. Only 1 place here sold them, before I could get hold of any they disappeared, sometime later (quite some time) the Mk 2's appeared. I never bothered.
As said there was a something that gave a "list" of the improvements performed, it may have been on the site of the retailer that sold them here to demonstrate the updates performed to the Mk2's over the Mk1's. But by then I think people had moved on. It seems rare in astronomy that poor initial offering is forgotten, even if the next is better.
Are they clones or are they agreed reproductions? Remember that the production was in always China.
I think you will find the "history" of the eyepieces somewhat foggy.
Have read more then once that the TS offering are pretty good items, and not "Bad". Question then is who makes those particular items.