Hey guys! Newb here, be gentle.
Anyway, being in the tech world for the past 25 years and being a part of the gaming world for just as long, I have been taught a few times.
A.) What you see is what you get
B.) Console developers are wizards
C.) PC developers are generally lazy ( or extremely held back due to the nature of their engines having to talk to 100 different architectures )
In my opinion, I think the PS4 will have the noticeable edge in multiplatform titles. Mainly due to how easy it will be for developers to port the original code over from the main development platform on the PC and slap it into the devkit and then test. Will be very, very easy for them to do that. Due to that ease, the devs will probably have an additional 2-3 months or more of pure optimization time with the code on the devkit environments. This will help even third party devs toy around with the PS4 more. Who knows, maybe the third party devs will even begin to play with GPCPU on the PS4 by the 2nd generation, and not the 4th like Cerny thinks. Extra development time provided by ease of development is extremely positive.
On the X1 side of multiplatform titles, it will be a bit trickier. Especially if MS does not build VERY good API's that will allow developers to tap into the functionality of the eSRAM with alot of ease and simplicity. If MS builds fantastic API's, then you will begin seeing developers put the eSRAM to much more use. But if they have to build the structure themselves, well .. at first, you won't have much use from the eSRAM.
Even then though, the PS4 just has far more raw GPU power. 32 rendering processors compared to 16 is a major real world difference. Being able to feed 32 processors to render your output means well .. pretty simply that the PS4 will be able to render a scene twice as fast. But added in with the memory bandwidth from the GDDR5, you have the PS4 being fed more information faster and processing that information twice as fast to the television.
X1 exclusives that are built from the ground up utilizing the eSRAM's capabilities will look much better in comparison to multiplatform titles. Especially if the group at the helm is highly proficient like Crytek.
Thats my opinion on the matter. And as a newb, please rip into me if I am completely off base.