We are talking about world and asset streaming, and level design possible only with an instantaneous I/O. The pc like differencies regarding res, frame rate and video effects are the less important aspects.
Even physics and interaction alone could be 100 times more complex using zen cpu, instead of being limited by the ancient and weak jaguar cpu.
It's a topic that has been discussed infinite times, but it seems that some people are not even capable to imagine structures different from what they have been seeing till now.
This is the first generation that has a technology that can provide a huge leap in terms of structure and level design. Until now we had an increase in streaming and loading speed proportional to the increase of asset quality. But this time, streaming and loading speed leaped 10 times more than gpu power, and that allows to let go many limits that games are experiencing since ps1.