After spending a few more hours in the game I have to say I'm increasingly more impressed and have take back what I've said about the torpedoes.
Firstly, they behave just like they should. I had a similar situation as before but this time I was close enough to see what's happening. This time I fooled the torpedo with a noisemaker and turned the opposite way to run away. After passing through the NM the torpedo entered circular search pattern and didn't found me after first circle, but on the second one it picked me up again.
Secondly there's no bug with torpedoes braking wire where they shouldn't. If you don't do any sharp manoeuvrers you can easily keep the wire intact. Provided it won't break on launch.
Also I found several nice touches to the game. For example, if you fire torpedoes during sharp manoeuvres (especially at sharp angles) it will get stuck inside the tube rendering it useless.
Another thing is that someone here mentioned that you can't break the towed array. Well, considering that signal strength from towed array drops significantly above 10 kts and shows 0 above 15 I like to imagine that the crewman responsible just automatically retrieves it at those speeds. I know it should take much more time than accelerating from 5 to 15 knots but at least it's better than nothing
One more thing to mention is that the game can be really satisfying. It feels really good when you use all your tactical advantages (thermal layers, staying near the surface when the sea is high, or creeping at the bottom if the enemy is shallow, using signal strength comparison to figure out his detection range etc), manage to get into the baffles and shoot the enemy at close range so that he can't do anything to avoid the hit.
Also, the AI seems a bit more competent at Hard difficulty, i.e. they're much more conservative with the usage of active sonar. One time I had a duel with a sub during which through the entire time I had no sonar contact with the enemy. I had to entirely depend on his occasional active pings (they can give you 1-3 pings and then stay silent) and direction of his torpedoes to kill him.
And lastly, you can play entire encounters from the tactical view. Even dodging torpedoes isn't that difficult (statistically I survived more attacks while not relying on a 3d view). I'm beginning to use the 3d view as an eye-candy tool when there's no immediate threat.