The Yasen subs are good boats. And very apable.
But in the time they have launched two of them, the US has launched fifteen Virginia class, which are quieter and as if not more capable.
The numbers are simply dwarfing the Russians in terms of their ability to go up against them...and don't forget those three Sea Wolves either.
Not to mention the English having now launched four Astute class...which are also amazing boats..