Xuechang Sun is the name of the master (best known as a cello maker) of a 60 man shop (last i knew, but it may have changed) in the Beijing area. 20 to 25 years ago his shop made the Eastman Strings line of basses, which is when I first became acquainted with his work. For several years David Wu at Sinoman in Ontario was the connection for the basses, and then Alex at Century became logistically superior, being both closer to me and in the same country. Sinoman had (has again, I believe) the full line of basses, which has not generally been true dealing with Century. The basses are available as plain wood, flamed wood, very flamed wood, "master", and one piece back "master". The basses are similar in appearance from one end of the line to the other, all having superior fit and finish, and the least one being properly made from my POV as a life long luthier, and having the kind of sound and power we hope for. From there it gets incrementally better, with the most noticeable technical difference to me (aside from the wood) being the attention to the perfection in the carve when I run my hands over the surface of the plates.
I do my own set up on all basses, and not all instruments I get my hands on are equally easy to bring up to snuff. I have had around 30-40 Sun basses and none have required extra effort (as some other workshop's bass have), though the quality of the ebony is certainly superior on the 2 Master instruments I've had. Both of those basses were placed with highly reputable players who continue to claim total satisfaction.
I did make a trip to China and explored the possibility of importing my own basses. I was surprised to discover that the existing importers are not gouging as badly as I expected, and while they may have had larger margins a few years ago, things have gone up in China more than here, and I could not do so much better that their relative convenience was not worth the price. I did find an undiscovered maker and bought a couple of his one man (master) basses for half the in China price of a VERY similar Neolsun. Not a coincidence that I mention that name, as there is quite a story there. I still have one of those basses for sale.
When you consider the value added that a serious set-up is, and the follow-up that a connected technician usually includes when you acquire a bass from them, dealing with your local dedicated purveyor has much to recommend it. Certainly true in the SF Bay Area where I am.
Bruce