That's because in a real world application, the differences are very very tiny. It was no different last gen. I have every CoD on PS, Xbox and pc (except for that crappy ghost), and between last gen's CoD games on both consoles, the differences visually in real world game play...was barely noticeable. One would be hard pressed to see the difference. However, xbox fans claimed there was a world of difference. Someone went as far as to claim the xbox version "curb stomped" the PS version (and no, it wasn't theseekar, but don't recall who).
Honestly, just play on your console of choice, the differences now are like last gen....not enough to deter anyone from playing on their preferred console.
I'm sorry but I had blops 2 on 360 and ps3 and the 360 version clearly outshined it on my tv.