Give me 14 defending in 15 (and the lower speed online) and I'm happy.
Been playing against the AI on 15 for a while and I love it - and on manual, I even enjoy online. It's been a good year for football games I reckon.
One thing I'm noticing more and more though, is that in PES (offline or online - and it's SO satisfying online), if I can pick out where a pass is going, I can block the pass and get the ball moving forward on a counter-attack. In FIFA, especially online, I can't do it - I can predict where the opponent is going to pass the ball, but you have to be stood in a pixel perfect-correct place, or the ball will just fly past you (or behind you). I see 15's defending system as less of an "artform" and more of a nightmare, it seems overly difficult and unrealistic to me (which I can back up with some truly mental scorelines).
In 14 (which I still get the occasional game on, and it's one of my favourite football games ever - I don't have to put it on manual to get a good game out of it online and the scorelines are reasonable too), I can intercept those passes much more easily (and the same happens to me, which I'd prefer - you have to up your game and pick a less obvious target).