I've lived in the Mainland or HK for almost 15 years, and you can find quality and workmanship that equals anything produced anywhere - it just depends on what you are willing to pay and how many Chinese friends in the know you have. Most things here are yearly or seasonal - clothing is quickly replaced and people like and buy new things on a very frequent basis. A lifetime-and-beyond jacket would be seen as a bit redundant if it starts looking 'old'. You also get composite leather and the like, but you get those everywhere.
You're much more likely to find vintage leathers in HK, but it isn't by any means impossible to find outstanding quality and individual craftsmanship in cities like Shanghai and Beijing (and Guangzhou has a few excellent export markets, too). Leather jackets I've bought in Guangzhou ranged from the thickest cowhide I've handled (these were probably from or for use in the far north and generally fur-collared) to branded, standard quality jackets - these were still in excellent condition when I sold them or gave them away five years later. Shanghai tailors tend to make leather jackets for the local market - these can be stretched/thin lamb or goatskin, but aren't designed to be particularly durable. Tony Leathers/Armed Front make solid stuff, but there isn't, relatively-speaking, a noticeably high demand for bespoke, bulletproof jackets when fashion jackets would meet most needs.
My luckiest find was a Shanghai tailor who took a look at a pair of expensive, super-thick repro denim jeans I had and wanted another pair in a similar cut and told me that it wasn't difficult to do and was amazed at the price I'd paid for them from a European country. She made me two pairs in denim of the same thickness in ten days and I've worn them all the time. Cost was a fraction of what I'd paid and they seem to be harder-wearing.
How's the overall construction and workmanship compared to other well-known companies? You already said that they have done a good job but what means good in terms of value for money?
