Once we see more it'll likely be more apparent how good it really is.I think this will be the flavour of UE4 discussion. People having to 'point out' how good it actually is. Perhaps we really are approaching the ceiling.
... Problem is even if we can tell a lot of us will probably still feel it's really not that big of a jump regardless of what the numbers would say, and the public would probably be even harder to impress as they'd just go "They looks like a 360 game!". Depending on how this unfolds I could definitely could see a gap like the Wii had with 360/PS3 not mattering as much, not unless we're seeing a huge jump in how big and open games are or something instead.