Have this year but both games downloaded as demo versions and repeatedly played extensively and, until FIFA, PES and then again the one and the other, etc.
I must say, I was blown away by PES downright. Especially in a direct comparison I noticed how little FIFA actually do play football. Ok, the presentation and all the trappings leaves at FIFA open mouths back, but the game itself is unlike PES downright grottig.
PES is properly the real football match by a mile, I had with FIFA increasingly feel I'd play ping pong or something ... So it looks already like soccer, but it plays just not so.
Do not misunderstand, I would not now say that FIFA is full bad and it also as I said advantages over PES, like the fans parched, licenses, etc.
But I am a really nice football game in which every game completely differently simply runs important. Especially with FIFA, I feel that a repeat of the actions on the court quickly.
This is because the ball physics in PES is so so well that the slightest movement results in a completely new game situation. That leaves FIFA already miss her very much.
CONCLUSION:
Who the football game can not be real enough and everything from a game (he) wants rausholen who must resort to this year definitely to PES.
Who the game itself is not as important and is more on Aha-effects and presentation, which is probably better off with FIFA.
My tip:
Download Both demos and decide for yourself.