Although I don't know how things are now with Chinese-sourced transistors, but back when I was doing hardware work on computer motherboards many manufacturers were having BIG problems with Chinese electrolytic capacitors, and counterfeited transistors.
The electrolytic capacitors issue is pretty-well known and details can be found on the web. The counterfeit transistor issue is (or was) a little less well-known, but I have seen TO-3 cased Chinese-sourced power-transistors which failed in service and when dissected were found to have 2N2222 transistors in them instead of the far more robust transistors which SHOULD have been inside the cases.
I also had very poor "luck" with Chinese-made 572B tubes.
Due to this history, I am VERY reluctant to buy nearly anything "electronic" from a Chinese source.
YMMV
Ken Gordon W7EKB