Don't get me wrong, the SU-35 is a pretty plane and it does fly really well. If it was what I was offered, I'd gladly take it. But given the choice, I'd still prefer even an F-15 and simply decline to take my opponent to the merge. It's very difficult to BFM an amraam and virtually impossible to defeat two. So whatever system lets me maximize the performance of that missile is the one I want to fly.
None of that mentions other known factors, such as the robust systems in the F-15 that have allowed them to take serious combat damage and still fly home. Know many other modern fighters that can take an entire line of geese (about 14) down one motor, 2 geese down the other, spend 20 minutes on RTB with a major engine fire, and still land safely?