Graphics: PS4 definitely takes this, but the difference isn't as big as everyone says it.
Audio: Not much difference between the two. PS4 has a sharper sound on its games, but Xbox has the better headsets available at the moment. So if youre going to be using a personal headset - Xbox
Interface: Not the best heading, as it could mean a lot. But im going to assume you mean navigating the menus. PS4 is easier to navigate, but that's because it looks (and feels) a lot more simple. It hasn't changed much from the other Playstations. People moan about the xbox, but I still find the interface pretty easy. But one isn't "better" as such..
Multitasking: Xbox. Hands down. Can be playing games while having other apps, TV, music, youtube, etc.. snapped/minimized to the edge of your screen
Apps: Again - they are both pretty much the same apart from the odd unique app.
Games: Personally, id go with Xbox. PS4 has some epic games (LBP3, The Last of Us, Infamous:SS, etc..) but apart from those, there isn't really anything else that is worth buying the console for (exclusive-wise). Personally id go with xbox for this one
(Could definitely change with things like The Order 1866, Bloodborne, Until Dawn, etc..)
Hardware: PS4 has the most promise. But nothing has really come out to push any of them to the limits to see what they can really do.
A lot of it is down to personal preference. You should look at what they all do, then make up your own mind. As people online will just be biased to whatever console they own. Some of the xbox ****ups before it was launched (which are now fixed) caused loads of people to get a PS4, so an online Poll will always say PS4 is the best.
I used to be a PS person, but I actually find the XB1 to be a much better machine.
Source of Opinions: I own both consoles.