8gig of DDR3 don't matter.
8gig of GDDR5 won't matter.
All matters is do you a machine that plays the next HALO or UNC?HARTED.
Basically, which platform has the hit games. The most powerful hardware has never sold the most in a console generation or had the most market share. This is why I think that hardware arguments in console gaming are ultimately pointless because how that hardware is used is ultimately up to the developer, not the consumer. It's not like comparing one washing machine against another -- all washing machines clean the same clothes, all consoles play different games.
Even in the case of multiplatform games, they're all probably just going to target the lowest common denominator.