I've used both versions. The differences are similar to differences between S-M-C 1:1.9/85 and S-M-C 1:1.8/85 -- the first version of both 85 and 135 is soft wide open, maybe better for portraiture, while the second version of both is brutally sharp from wide open, and closing down only get sharper. I would say the first version is average, but he second version of S-M-C 135 is one of the finest 135s ever produced during film era. The Nikkor 135/2 (manual focus) may be a little better, the jury is still out on that. The modern Zeiss T* 135/2, Nikkor AF 135/2, and Canon 135/2 L are #1, #2, and #3 best 135s available.
That BIN price is okay for the second version, but way too high for the first...