All I can see if potential proof that, with regard to the top titles on each platform, EDGE reviewers tend to score lower (exceptions aside obviously) and that they inherently prefer the 360 titles.
That isn't bias in a conspiracy sense - they deliberately mark down PS3 or inflate 360 - so much as a lapse in maintaining outright review neutrality - i.e. reviewer genre/gameplay mechanic preference has crept into their scores a little and the reviewers simply prefer, as an example, Mass Effect 2 over God of War 3.
This happens all the time with reviews, though, and is particularly rife in videogames reviews, so I think all anyone should take from it is an understanding that, a few exceptions aside, EDGE slightly prefer the titles on 360 to PS3 from that sample and in general does seem to score more harshly than other sites.
Try to be reasonable... its easier than you think...
