Seems slow compared to PES. FIFA players will say PES is too fast...
Defending is not dissimilar between the two, you need brains; timing and positional sense rather than to just dominate physically. Passing is not a million miles apart aside from the speed. The three main differences are shooting, dribbling and the goalkeepers. Dribbling is a bit too powerful on PES, you can jink through players a bit too easily for me. FIFA has had the easier dribbling for a few releases, but it's more to do with the insane amount of tricks. Neither perfect for me. Goalkeepers on FIFA are much better. On PES they spill the ball into dangerous errors too much. But they are designed to go with the shooting on PES, which is floatier and takes more practise to get right. Shooting seems much easier to me on FIFA. The curling shot on FIFA is overpowered, so goalkeepers are often Yashin-like to deal with shots. There are also some flaws on particular angles.
Graphics - FIFA has the overall experience, although in terms of the player models they still seem very vacant and robotic. PES wins the models for me as they use photo scan software and the faces are perfect and animations strong, which is what I expect from Konami. EA Sports haven't been strong in this respect across all their games. FIFA dominates in the menu layout.
FIFA is much better in terms of sound, in the stadiums the atmosphere is intense. Probably too much for many games, they are over-egging it, but they have spot on chants which are obviously recorded. Music is also better, although I do like the charming offbeat stuff on PES in comparison to many well known artists on FIFA.
Licenses isn't an issue, FIFA obviously wins. PES dominates in editing and the personalisation of the game. I don't think those two things will ever change.
They are two good games. Personally I think it's much easier to go from PES to FIFA than the other way around, FIFA is easier to pick up and play. I still prefer the way PES 12 plays more, and that is the thing I overwhelmingly care about. But I'd go with the overall opinion that FIFA 12 is the better game and a very good one at that. It looks like a strong game and for the last 3 releases plays like a strong game, it only comes down to how it feels to you after that, if you are used to playing PES.