The Yasen SSN/SSGN hybrid nuclear subs are extremely good vessels by all counts.
They have a tremendous and very varied and flexible weapons load out.
But they are building slow.
By the time these two new subs are commissioned, the Russians will have five of them, and at that point the US will be putting out its 15th Virginia class sub (and 18 if you throw the three Sea Wolfs in there). The Virginias may not be as big as the Yasens, and may not have as large or as flexible a weapons load out, but they are nonetheless very dangerous subs...and the equal to the Yasen in terms of stealth and anti-submarine warfare.
Just the same, any Yasen will be a very dangerous and capable foe. Very good technology and very good capabilities.