from what i test through fifa10 demo there are pros and cons:-
Prosvariety of animation
nice commentary
nice goalkeeper A.I.
good graphic (except the weired player face and ungly jersey font

)
Conslook like icestaking on the pitch, not so real (players like mabuk dribbling ni

)
all players look the same, in term of ability (lol a defender also can perform those trick like striker, very unrealistic)
can use any player dribble pass through at least 3 opponents (again all players can be messi/ronaldo type)
some funny foul will be whistle even it is a good interception without slide tackling (happen too many times)
All the above are my own personal thought about the demo, by using experience level, play more than 20 matches. And 1 more thing, after playing 20 over matches i just start to feel boring about the game, coz can even use Marsellie/ Chelsea to trash Barca 3-0/ 4-0 most of the matches...
Like zeronehza said, fifa10 have its advantages (a credit to their production team, after so many year of setback) but seriously i'm not really agree on the part you mentioned about you need to do motion capture for lots of player in order to present/ resemble those skillful players in-game.
Just like WE/PES series, they don't have motion capture technology on previous ver., but we still can really feel/ differentiate each of the skillful players in-game. For instance, if you control Drogba, you can feel his physical toughness towards his opponent, and his accuracy on shooting, if you control Fabregas, you can perform pinpoint through pass just like his real life but very rare can score a world class goal, if you control Terry, although he is slower than some of the top defender in-game, but his positioning and reaction on clearing the ball is top class in-game, just like his real life. If you are using Walcott, you have the pace and dribbling skill but when in front of goalie, his shooting accuracy is very low....and etc, just to name a few. In fifa everybody can possess the perfect passing, everybody can have those superb dribbling skill, and some defender can even score a world class goal like Drogba, very unrealistic...
That is the "magic" of WE/PES series. The production team able to develop a game that's so freaking real like what you seen in real life football. Of course they can't match with good graphic & animation like fifa series, but like i post before, the "individuality" on each of the players in WE/PES is the one that still attract so many gamers to play the game. You feel like you are really control a player that resemble like his real life counterpart. That is the reasons why there are still so many hardcore ppl buy and play WE/PES series, despite the graphic still not look next-gen like fifa.
For me, Fifa series is just beautifully package with nice graphic/all official kits but still lost the core gameplay/ soul for a longevity gameplay. In WE/PES all the goal are so unpredictable and satisfying (Even until now i still feel shock that i score a goal that i never see before after a year of playing, during my recent online match with a Hong Kong player). In Fifa i just dont feel anything exciting when i score a goal, coz it tends to be looks the same/ predictable.
So for me, i want to play a real football game that give me the excitement and passion, therefore i choose WE/PES series. Still Fifa look arcadey to me, and feel bored quickly.
Of course, WE/PES still have some flaws, especially on next-gen version. Nevertheless, i would rather spend my money on WE/PES that can satisfy me when playing with mate (we shout and scream when score a goal), rather than Fifa that turn bored so quickly.
GAMEPLAY wise, WE/PES is still the best footy game out there. Isn't the GAMEPLAY is the most important criteria for a game that can last long and still have fun playing it?
This post has been edited by SeanWong: Sep 13 2009, 10:45 PM