Having had both as long as possible, I have to say that a VERY much prefer the PlayStation 4, which is the exact opposite as last generation (I only played the PS3 for the major exclusives), when I played nearly everything on the 360.
On the PlayStation 4, I've really enjoyed how quick and snappy everything is. Updates are fast, the UI is easy to navigate and laid out in a logical fashion, the games look amazing, the DS4 has been dramatically improved, and the online experience has been great.
On the other hand, I've been pretty upset with the Xbox One. It's quite slow and cumbersome in comparison. Updates/installs take an eternity (1 hour and 12 minutes for NBA2k12 is NOT acceptable), the interface is a mess, Kinect is my newfound nemesis with it's piece of crap voice recognition (60% accuracy on a good day), and I don't like the bumpers on the new controller. Heck, even navigating around the dashboard is done at a low framerate and it lags. How do you screw that up so bad?!
Also, VOICE CHAT ON THE XBOX ONE IS BUGGIER THAN A RAINFOREST. Half the time people in your party forget to enable voice chat, the other half struggle to get it to pipe through their headset instead of Kinect, so it sounds like an echo chamber. Nothing is more fun than 5 minutes of "is my voice coming through the headset mic, or still the Kinect?" tests before starting up your game. Real cool.
And to steal from my own
my rant on the Xbox One UI...
I don’t like the Kinect at this point. Sure, maybe I’ll get better as time goes on, but as it is now, using Kinect is embarrassing, even when you’re sitting alone in your gaming room. If you really want to feel stupid, show your wife how “cool” the Kinect is and watch as she laughs at your “kind of neat if it worked well” $500 console.
Resorting to controller is almost preferable to using Kinect. Almost. The way that everything is “organized” on the Xbox One is beyond stupid. Random tiles flip around in place and there’s no cohesion to the style nor experience from one page to the next. I get that you can pin your favorites in place, but any time you veer from your favorites, you better fire up Google Maps, because THE SEARCH IS ON.
tl;dr: I'm really happy with the PS4 so far, but I'm really irked by the Xbox One at nearly every turn. Microsoft goofed, and they better rally and turn things around before they become nothing more than a media box this generation with a random exclusive worth playing once or twice a year.