ONI: Chinese SSBNs Much Noisier than 1970s-era Soviet Boats

Or at least that the conclusion that they've reached at FAS:

China’s new Jin-class ballistic missile submarine is noisier than the Russian Delta III-class submarines built more than 30 years ago, according to a report produced by the U.S. Navy’s Office of Naval Intelligence (ONI).

I haven't had a chance to read the original report, so can't assess whether that's a completely fair summary. This suggests, however, that China's survivable second strike capability isn't very survivable at all, and that as a practical deterrent the Jin class isn't all that much better than the Xia. The effectiveness of the Jin as a deterrent against the United States is further limited by the fact that the effective range of the JL-2 SLBM would force the Jin to sortie well beyond Chinese home waters in order to threaten the continental US. Of course, targets in South Korea, Japan, Hawaii, and elsewhere would be well within the JL-2's radius.

As Yankee Sailor noted a while back, "it's not all about us." The Jin class aren't a terribly compelling deterrent option against the United States, but they do lend prestige to the PRC, and remains relevant to China's deterrent relationship with India and Russia.