Nikon AF D 50mm f/1.4 optical performance

There is any optical difference in performance between the previous version made in Japan and the actual one produced in China?

I don't think there's any real optical performance. The Chinese version was just cheaper to make for Nikon. Don't qoute me on this as this is just speculation/rumor. I don't have any real evidence.

I also own this lens and it's great!!!

I think mine is the Japanese version, btw.

There's no difference. All Nikon products manufactured anywhere else outside of Japan are under the supervision of Nikon. I am a foreigner living in Japan and I bought this lens 2 years ago and was surprised to learn it is made in China. I was told there are no more made in Japan. If someone bought this lens prior to the "Made in China" phenomenon, chances are the lens must have have been made in Japan. But all of the classier Nikon lenses like the 70-200 VR, 400 f4 (both of which I have)17-55mm, 17-35mm, the new 105mm VR to cite some are all made in Japan. Less expensive lenses, it seems, are being made in other regions.

With my 18-200mm VR and 18-70mm lenses I seldom used the 50mm f1.4. But it's always in my bag and use it on low light situations where it shoots great and better than the first 2 lenses.