Let's see what we think of the "vaporware" PAK FA. How do you think its going to be like? FSW, trapezoidal, delta, biplane, triplane, whatever......will it be a direct equivelant to the F-22 or to the F-35?
Electronics equipment : i think it will be inferior to the F-22. This is a tradition with all Russian aircrafts. For some reason they lack behind western technology in electronics, though their software capabilities offset somehow the lack of processing power. And since, both Russia and India cannot compete with the cash flow the Americans spent on their weapons, i don't think this will change.
Performance : On the other hand, i strongly believe, that in terms of performance the PAK FA will be at least equall or better to the F-22. They already know how to design a supermaneuvrable fighter (Flankers), they have explored for over a decade the post stall flight regions and they routinely "violate" the pre stall flight envelope with maneuvres such as cobra. They also know how to make a engine immune to any attitude the aircraft may fly, and that is also long before americans.
Stealth : Sure thing, the theory of how to measure a surface's RCS was made by a Russian and Russians were always masters on mathematics. This theory has been improved, and along with the todays supercomputers (far better than what Lockheed used back in the 90's to shape the F-22) should make the task easier. But, one thing remains unchanged, you need a huge amount of money, to build it and test it. The russian thinking dictates that a fighter won't live enough in case of a war and thats why they prefer cheap fighters built in numbers, so a proper stealth effort seems like a luxury for them. They also have no experience ( at least they have never present something stealthy) with such technology, so i don't think that they are going to build something better. Maybe they will equall the Raptor in that field, but not better it.