Pakalolo has a point that in the forums it's common place to mention China as the explanation for why something is lower quality. We should all keep in mind that China builds rockets, submarines, stealth fighters, super computers, iPhones. Note I'm not intending to go into politics, just manufacturing. The problem is that wanna be entrepreneurs from the US without any knowledge of how to write an engineering specification or a contract go shopping randomly for the lowest bidder to supply components. Of course they are in danger of getting low quality.
Now take Arizer, all their equipment is made in China, only a partial assembly is completed in Canada. Arizer makes very well regarded high quality items, clearly because they've figured out how to work with suppliers. Maybe they don't go with the lowest bidders...
I truly respect the design work and innovation done by the niche contributors like RBT and the VapeCritic but they have (or started with) no training or experience in international manufacturing. These are good guys, but would I hire them to run a division of a company I owned, hell no, they don't have any qualifications. They make very small orders that are a tiny trivial portion of the customer base of some glass or metal component supplier in Shengzen. Suppliers there, or anywhere, will give you the bare minimum you've contracted for and nothing else.
Sorry for that rant. I'm just saying, it's not a China quality problem, it's mostly a problem with lack of experience and economic clout on the part of the American vape company owners. If the glass in a v2 Splinter is not good (by the way I love my v2 Splinter and have no issues with any part of it) that's RBT's responsibility, he could have chosen to buy thicker glass in China but didn't want to pay for it. Maybe I don't want to pay for it either...