I think many people here just vote for Kh3 because its on a much more powerfull system.
I never said WW would be more demanding, i just said that for me (personally) it does look a bit better. Both game look very similar though in terms of textures and lighting and used colours. Only difference i can see are abit darker colours in KH3 (what i dont like that much) and much more particle effects in Kh3 (which dont make the game "better looking" for me).
I doubt many people even watched the videos who said "kh3 looks lightyears ahead" but okay.