the ps4 has a better interface imo. but it's not that the ps4 one is great, but it's just very straight forward, fast, and simple to use. and the xbox1 interface IS TERRIBLE. i cannot stand the UI for the dash on xbox1. i can't believe how much worse it is than the 360.
for instance, friends. i had blurredvision (and many other people) on my friend list. however for some reason, some people are now on my "followers" list instead. there is no rhyme or reason as to why some are on my friends list and some are on my followers list. but for him, i am on his friends list.
so what this means is, that he can see me pop online and see my scores on games under the friend filter. but on my end, i can't see him pop online or see his scores on games. makes no sense why he didn't stay as a friend on my end.
then you have the "everything is an app" bullshit. pulling up the friends list is such a headache now and so is reading messages. it's just so clunky and simply terrible.
now that said, as far as the home theater experience goes, i don't use either of them for bluray playback because they both suck ass for bluray playback compared to a standalone. i've used amazon prime and netflix on my xbox one, but that is rare. the quality on both of those is crap compared to an actual bluray.