I got FIFA 09 for my birthday a couple of weeks ago, and I didn't think it had the 'feel' of PES. I've been playing since ISS on the SNES and I've found previous FIFA games to be so bad as to be mostly unplayable. FIFA 09 is in a different class though. EA have worked and worked to make what was an awful experience now something quite impressive. After a couple of games, watching your team holding up the ball and stringing passes together is very enjoyable, and the satisfaction of placing a shot and watching it go to the right spot in the net is awesome!
So after a week or so, I went back to PES and I have to admit I was pretty shocked by the AI. The ball moves so much nicer in PES (for the most part) and there's a much better 'feel' to it, but the AI is shockingly bad, to wit:
Slide tackles from players you aren't controlling leading to penalties, red cards etc are awful. I've managed to cut down the amount of times this happens by switching players before the tackle but since the AI seems to randomly pick which player you're switching to, this is by no means guaranteed.
The ref has a real tendency to interfere with play, he frequently collides with off-the-ball players!
The pinball effect on the ball physics. I hope people understand what I mean by this, I don't how to describe it more accurately. For example, the way the ball rebounds off keepers and to the feet of a striker while the defenders are running into each other or how you can put a tackle in on a player like Torres, Lavezzi etc and they simply bounce back onto the ball and away!
The AI control of defense - the CB almost always moves out of the box to tackle a winger, leaving you with the choice of switching to the CB and moving him back into position and then leaving the winger to whip a cross in, or leaving a couple of yards for the opposition CF to plough through (not much of a problem against the AI admittedly, but an easy way to give goals to a human opposition)
The GK. Dear Lord, the GK! Huge gloves, loves palming it away into the path of oncoming strikers and then lying on the goal line as if he's been shot. Or helpfully making an 'O' shape with arms and legs for the CF to shoot through!
The tendency of world class strikers to consistently put the ball straight at the keeper, or not use their other foot to place it, and skying it into the crowd. Luckily this actually works in my favour since it keeps my opponent from scoring plenty of goals that in FIFA would be straight in the back of the net.
The moving and passing: how many times have you had a nice through ball waiting to put through from midfield, or a short pass to your playmaker, while running forward, only to watch the ball travel towards your CBs? Manual passing can alleviate this to some extent, but not enough. For my money this is the single worst flaw in PES, and the one that needs to be rectified most quickly. There are steps you can take to work within the limitations of PES' AI but it is quite frankly retarded to watch, for example, Gerrard play a ball back to Carragher when Torres (in whose direction he's moving and facing and in which direction the stick is therefore being held) is in a great position between the CBs.
It's easy to say, for example, you need to play the game more etc etc, but that's not really the point. Professional footballers are not children or idiots, and that's what the AI makes them out to be. You can work with what you're given and have a really enjoyable experience after putting in the graft, but to not have something simple like a pass work is pretty dire. It's not hard to rectify, FIFA have managed to do it!