For the average consumer, the craphical fidelity is at such a high level now that they won´t notice any difference. I don´t know anything about how these consoles work, what I do know is that it isn´t as easy as saying "50% more powerful" since alot of the performance is software based aswell.
There is a reason why Blueray hasn´t taken off and eclipsed DVD´s: one part is the digital content age where more and more people streem movies. But the big thing is that most people don´t find a big difference between av BR movie and an upscaled equivalent of a DVD movie. I think the same thing can apply to PS4 and X1: even if PS4 will have better graphics (which I actually doubt at the moment, parity will be the standard I think) most people won´t find that there isn´t any difference at all.
Btw, the whole PS360 graphical debate was silly from the XBox fanboys: the difference was minimal at best in the previous generation too.







