Because the game is much better than its predecessor. The gameplay has become a bit slower and feels again well received. The new "Become a Legend Mode" also makes a lot of fun. However, I think the other players in this mode, partially a bit stupid, so they play sometimes very pomadig and unnecessarily risky. That's just when you're forward, a bit frustrating. This does not mean that those not in a position to bear attacks forward, but there remain some unnecessary halt hang. There is in this mode, some small drawbacks compared to the PS3 version (eg no team training). This also applies to other modes. So, for example, lacks the "Champions League" mode on the PS2 entirely what one already recognizes the lack of "UEFA Champions League logo" on the PS2 cover. Nevertheless there "PES 2009" a very good figure on the PS2 from.
Who liked PES 6, which is also like this game. A purchase is worth, in my opinion, also due to the low price, definitely.
Incidentally, the issues raised by many Interchangeable bugs or game crashes are never happened with me.