I'd imagine it'll be the usual story where XB1 is 10-20% lower resolution which after upscaling is only really noticeable when run alongside the PS4 version. Hopefully there won't be any detrimental frame rate issues, I doubt it given that GZ ran smoothly and the Fox engine seems very well optimised.
To be safe, I'm getting it on PS4 as pretty much all of the preview/reviews seem to be on that system. If Konami are making that available over the XB1 then presumably they feel it gives the best experience, even if the difference is small.