I play PES over FIFA this year, something I haven't done for a while.
The new impact engine is part of the reason why. The one in 11 worked fine, on the whole, but they've tried to be too clever by adding a gimmick.
The biggest issue for me is UT not running properly, even today - despite it being at the focal point of the game and part of the special editions.
PES might not be the most realistic game to play ALL of the time, but it provides me with a lot more fun. Having all of the PL stadia in the game helps the presentation.