[crote]

I've got the same experience.

Chinese manufacturers can do absolutely amazing work - provided you can get them to care. In general they'll manufacture exactly what you ask them to. They are also very happy to do manual labour to get the job done.

But for most stuff, don't expect too much feedback. Asking for feedback on a design to optimize it for production didn't really produce anything useful, and they manufactured designs which contained obvious mistakes.

In general, you simply get what you pay for!