There will be an advantage for some, but then,that advantage has been available for years. Just predominantly in Pro Gaming circles.
This won't turn a bad player into a good one though. It will enable a good player play that little bit better.
i think you're underplaying it. it's definitely goign to give some people an immense advantage. Good players will be THAT much better. Bad players will be slightly more competitive, and your middle tier players will be able to actually put up a decent fight against good players that don't have one.
Think of a game like Halo 5. Look how many different buttons there are. You'll sacrifice a lot not having the ability to use a lot of the different buttons in the most efficient and quickest way possible.
I'm going to bet the Elite controller is going to really change the competition