I guess most likely nobody can tell you his experience with
this lens as this is a very rare variant. I know of 3 other Zykkor 135/2.8, but this one is completely new to me (occasionally I saw the auction on ebay yesterday).
My 5 cents in this matter:
- On the one hand it is "hard" to get a bad 135mm lens, as this is a focal length which almost any manufacturer mastered well
- On the other hand Zykkor is a classic 2nd tier trading brand that had their lenses built by different OEMs.
As always with such brands, it is kind of a lottery whether you´ll get a keeper or crap.