While not specifically about FIFA, I thought this article was interesting:
http://www.kotaku.co.uk/2014/11/18/pro-e...ats-enough
Now, as my past posts will probably suggest, I am one who generally favours the football sim that plays better than the bells and whistles outside of the gameplay itself. However, I can understand where this guy is coming from, as some of the features make for a more expansive and interesting game. Things like menus and commentary for me are moot points. I couldn't care less what a menu looks like as long as it's functional and I almost never have the sound on when playing football games. The other thing is lack of licenses in PES, though it does have community patches to help give real names available. Not a deal breaker for me, though I understand there are fans who want this stuff.
However, what I think is important is making certain features better. I don't know about PES 15's copy of Ultimate team, nor am I a big online player, but if they were to provide/invest in a decent online service that can at least look to provide a similar quality to FIFA, there's no doubt in my mind that a lot of players would consider PES.
Where FIFA for me is much better is Career mode. I hate the way PES14 didn't have an actual calendar and the transfer system is more about rewarding patience than actually simulating real football, never mind there's no real dealing system (i.e. you just sort of choose who you want to buy and hope it works out). Then there are totally random elements, such as which jobs are offered to you or the mood/motivation of the players (that last one just irritates me). From what I gather, PES15 doesn't necessarily improve these much.
Thing is, I think for gameplay purists and those looking for the most realistic simulation when in games, PES15 seems the better game when comparing the two (certainly the case from my own experiences this year). However, while I and I'm sure many other will be prepared to overlook the flaws for better gameplay, I do agree with comments saying that Konami must do much more to make the overall experience better. Simply put, I remember when I first started playing PES14's career mode and just thought it felt 5-10 years behind the stuff in FIFA.