I think the review you should all trust is IGN. The game is very good , yes it does have slowdown but a good game nonetheless.
I cant say i've noticed the slowdown much at all on the 360 , the usual slight slowdown if everyones in the box at a corner but it doesnt boher me in the slighest & is barely noticable.
The ps3 sounds as if uts slightly worse. But i wouldnt hit the panic buttons , it'll still be good. Pro-G's article while slating it still said it was a good game, i would reckon the low score is more to do with the disapointment that there is slowdown at all on what is supposed to be the best console there is (debatable) not that the slowdown makes it unplayable.