I've had two China bikes in the past, a GY200 Lifan, and a Huoanio HN125.
The Lifan was a heap of junk made out of pot metal and only suitable for use as a boat anchor. I bought it new and it had self destructed in under a year.
The HN125 was much better. I bought it second hand when it was four years old and ran it as my ride to work bike for a year. It was good, cheap reliable transport and the build quality was not too bad at all. You had to keep on top of the chrome with regular dousings of WD40 through the winter months, otherwise it was fine. I sold it for fifty quid less than I paid after 5000 miles and 1 years use. Bargain.