I have two MK-319's - one with the floating dome PE mod, and the other with no mods. I don't know whether either or both is Chinese - I got them both on ebay. One has a red Oktava logo, and the other one (the modded one) white.
I agree about the lack of consistency. Before I sent the modded one to Mr. Joly, it was horrible - unusable -- there were thunky pops with vocals, and it generally sounded crappy, lending an unwholesome harmonic distortion that sort of sounded like a cheap horror movie (I know that may have applications, but I don't have any projects like that right now).
The unmodded one was servicable from the beginning, but vocals still sounded kind of thin. When I got the modded one back, it was totally different - no gratuitous popping, utterly quiet (weird how you don't notice how much noise your other mics make until you hear a really quiet one - kind of sucks, really), and a very full and pleasing sound with good harmonics. My voice is still quite bad, unfortunately, but at least now that's the only suckage in the recordings. I have yet to try it out on a real singer. I also plan to use it for recording samples of various things around the house.
I'm still using a pair of SM81s for acoustic guitar, because the sound is dreamier, but the Oktavamod certainly has a claim for recording tracks that sound a *lot* like the guitar itself.
About the only drawback is that I'm now afraid to drop it, because it sounds so good, and that floating dome doesn't have much support (Joly warns about this in the mod description) - it feels sturdy enough, but I'd hate to dent it -- just have to be careful. Sorry that I have only subjective information -- I'm pretty much a novice when it comes to recording (I have been a musician with a decent amount of studio experience for a couple decades, though).