The PS4 version is going to be built off the XB1 code. I can't see bethesda, who has a very close relationship with MS, making anything better about the PS4 version.
If so, the XB1 version should look worse. There's not many 1080p open world games for XB1.
Depends really, if they use dynamic or not. If it's locked 1080p (which I'm hoping it isn't) then I'd guess the IQ is medium at best. It's definitely a big step up from Fallout 3.
All that aside it looks pretty good to me. Will it prevent me from enjoying this for hours on end on my Xbox? Hell naw.