Most of them will be good quality but I am sure there are junk products made as well it all depends on the factory and there standards.

I ordered some carboChinesese mountain bike rims and had them built up this spring. I have beat the snot out of them for around 1200 miles this summer. A mix of all mountain and cross country riding with just about anything you can think of. They have been the best wheels I have ever owned and are still true to this day. Nothing takes more abuse than mountain bike rims and this does show that cheap Chinese carbon fiber can be very high quality.