In regards to GPU bus width what you have to think is that back when PS3/360 were released 256bit buses were still pretty much exclusive to all the high cards and 128bit was deemed as 'mid-range'
5-6 years later and that's not the case any more, Nearly all the graphics cards in the modern 'mid-range' price bracket now all have 256bit buses, Except for the odd few cards that have been released on borked dies to fill a set price gap ( GTX 460 768Mb comes to mind )
I would really be surprised if the consoles didn't at least have GPU's with 256bit buses.
5-6 years later and that's not the case any more, Nearly all the graphics cards in the modern 'mid-range' price bracket now all have 256bit buses, Except for the odd few cards that have been released on borked dies to fill a set price gap ( GTX 460 768Mb comes to mind )
I would really be surprised if the consoles didn't at least have GPU's with 256bit buses.