Was there are a reason you did not include the Akula Class?
And one other thought: I remember at Chicago's Navy pier, a kid, not me, asked a Navy CPO from a Perry Class Frigate if he was concerned about 'Alfas'. His answer was that they were fast, but an Alfa was not going to outrun a helo. So, as noisy as an Alfa was (remembering sonar performance was poorer back then), a helo or an ASW plane is way faster and with good tracking information, even the speed of the Alfa is not enough to save them.
I would almost say that an Alfa's greater strength is its deep diving ability.
I guess my thought is that an Alfa's capabilities should be respected, but it is not really a terror. I might be more frightened of a Tango on ultraquiet than an Alfa...
Just my opinion on the subject.
Remember that the evil which is now in the world will become yet more powerful, and that it is not evil which conquers evil, but only love -- Olga Romanov.