They are almost identical,the PS4 just has more RAM and a somewhat better GPU. But since they are so identical you will hardly see any difference between them in multiplatform releases,although it was kind of funny that the Witcher 3 ran better on the Xbone on launch. I played the Destiny demo on the Xbone after playing it for months on the PS4 and I did not notice any difference even tho it is in a slightly lower resolution,and I have to admit that the Xbone controller is better than the PS4 one. Networking also feels like its better on Xbone,unfortunatly no Hawkmoon yet.