You clearly dont understand what i am talking about. Honestly i dont care how "big" the game is, it is good programming practice to keep your code as efficient and concise as possible, i am speaking of the correlation where the more advanced you make a console and you make it for an older less powerful product YOU MUST COMPENSATE for the deficiencies of the product.
Disc size is not that big of a deal. It more the hardware the PS3 is running which is most likely going to cause problems vs the xbox 360 version PS4 and new xbox. You can also cut content out which was the case for PS2 games also released on the PS3.
I would be more worried about the fact the PS3 uses a weaker GPU/complex CPU along with limited RAM over the xbox disc space. That is far more of a bottleneck.
Again we don't know which consoles the games are being released on yet.
You're right it going to suffer due to being released on 4 different platforms.