Today, watching some videos in one of my favourite sites, I´ve found a comparison between Assassin´s Creed for XBox360 and PlayStation3.
It´s quite impressive to see that XBox360 beats the PS3 up in this game. Some people say it´s just a contrast or gamma adjustment issue, but I don´t think so. We must trust the GameTrailers people to be professional and to have made the comparison with the same adjustments.
In the XBox360 version there´s more detail and, to my eyes, there´s some cool HDR which doesn´t appear in the PS3 version (see picture above).
It´s true that consoles need some time to do their best, and the PS3 is much younger than the XBox, but for the same reason, it also has better hardware (in theory).