Two comments on this:
The best way to kill submarines is to have the intelligence that they are about to go to war and then eliminate them before they make it out to sea. The Ohio SSGNs are a near perfect system for sitting off of the PRCs shore and taking out the PLAN sub bases through saturation attacks. There's a reason, folks, why the Navy is going to Blue/Gold crew them and is thinking about forward-deploying two to Apra in Guam. The idea that the ChiComs could do the preparations and staging necessary to successfully close the strait and successfully invade Taiwan is ludicrous at face value.
The second-best way to kill a submarine is to detect it while at sea and have another sub eliminate it. I find it difficult to believe that PLAN quieting techniques will ever really match advances in US hydrophonic detection/analysis technology. Beyond that, I recall that there was an awful amount of attention and money going into the use of blue-green lasers (including from satellites) to detect the movement of submerged subs ... back in the mid-1980s. 20 years on, I have to wonder what ever became of the program...
The PRC's posturing is bluff. They've got some bucks now and are upgrading assets, but I seriously doubt they'll be able to sustain their military endeavors.