We don't know. However, from the results of last few years (policy formulation and technology acquisition), it does appears to be too bad. Chinese leaders seems to have a good grasp of affairs and intents of foreign governments, didn't really see them cornered and out-maneuvered or making huge blunder in the various crisis so far. Technologies seems to improving, how much is from espionage, we don't know.
Anyways, Chinese intelligence service is either very good or very bad in the news reports depends on the story they're running and that in itself shows at least it's doing a good job of keeping things under the lid. After all, you don't see hackers exposing internal emails of top level communication like what going in the middle east right now.
Anyways, Chinese intelligence service is either very good or very bad in the news reports depends on the story they're running and that in itself shows at least it's doing a good job of keeping things under the lid. After all, you don't see hackers exposing internal emails of top level communication like what going in the middle east right now.