My view is that although the PLAN nuclear sub force is not as quiet as the USN subs of the same generation, the article may be overstating the quality difference for political reasons, as many of the manufacturing method improvements from the civilian sector and ship subsystems are already incorporated into SSKs like the Yuan class, and economies of scale alone would have demanded similar incorporation into the SSNs like the 093 and followons. The only remaining thing that separates the PLAN SSNs from matching USN quieting level is the nuclear machinery systems, but Chinese use turbo-electric systems rather than direct drive systems like the Russians or the US, so the quieting approach would come from a different angle.