I don't like seeing players with 54 speed as well, but pes2008 is simply too fast for me to enjoy with proper stats. I said that, not to imply that now PES2008 is slower, but to point that the speed does not affect the AI difficulty.
For the rest I agree, the stats decrease pass speed etc. There should be a engine value that affects overall game speed - not the way that kitserver speeder does it (which just lowers the framerate), and hopefully we'll be able to find it eventually.
And no, WE2008 5 stars (and 6) is not equal to Top Player PES2008.