Sounds to me that the updates to the AI evasion doctrines are working well. They're actually using the decoys effectively, almost as well as a human player would.
Of course, defeating the decoy is as simple as having a good initial solution and determining his evasion course post-launch. If you know this, you know where he is, where he's going, and where his decoys are. But if you just expect your torps sensor to handle the task for you, then you will likely be dissapointed.
