@author: I don't get why you ordered this from JLCPCB in Shenzhen when there's aisler.net in Europe, which would have been much cheaper. No shipping fees and no import taxes.
Nope. JLC every time here. Never a problem.
I never had quality problems. I remember reading an email with the report from an electrical test from one of my boards, so I don't know why you say they don't do it.
I only contacted support once and it took them 2 weeks to respond. Could be better I guess, but my experience with other PCB companies tends to be worse. I'm used to never getting any replies at all.
I did feel kind of cheated when they sent me an elaborate market research questionnaire. In exchange they offered in-store credit. I took the time to fill it out and send it to them, but I never got the credit they promised. I never contacted them about it because it wasn't such a big deal, but it still left kind of a sour taste.
With JLCPCB on the other hand, I've had things stuck in customs for 2-3 weeks multiple times due to documentation issues and then I had to hunt down someone at JLCPCB with the authority to provide me with a fixed invoice.
That said, I've heard that the JLCPCB DDP terms work great (where they pre-pay customs for you) but they didn't allow that in my price range.