I actually gave this another go over the weekend and it's actually quite good. I managed to play about 7-8 games and only two were unplayable due to the lag. The actual game engine makes for a very good game of football. The football is very intuative and, as usual, the ball physics are very good again. It's just that it isn't implemented particularly well. If you can get games like COD4, with those gorgeous graphics with bullets and rockets flying all over the place, and not a hint of lag, slowdown or judder on live. Then why can't they get 22 men to run around a pitch, smoothly? And the replays... I don't understand why they are so botched up... Look at Halo3... there's much more to deal with there.
Oh and they have made it way, way too easy to score. Most of my games were 5-4, 4-3, 3-3 etc and I think they have taken the wrong path with this. PES has always been tough but with a sense of achievement when scoring a goal. For some reason, they have taken the old FIFA route of 30 yarders every game.
This is a real shame because, at its core, is a very good game. They just need to employ some programmers who are up to the job of coding the great ideas. They are obviously trying to do things on the cheap and rely on the reputation of the series to sell games rather than employ decent programmers or train up the ones that they have. It feels as though they haven't moved on from the PS2 days and they should take a good look around at the software coming out on the next genners if they don't want to go the way of Atari etc.
So, I haven't voted, but would probably go for a 5 or 6 at the moment, rising to a 7 or 8 if the lag/judder is fixed. Compared to the overall quality of games like COD4, PES2008 just feels like a budget title.