I own both. Love both.
I got te XB1 for KI, Dead rising, Ryse, Halo, future Gears game, and the UI is better IMO.
I got the PS4 for multiplatform games, Infamous, Killzone, The Order 1886, possible God of war Game, Uncharted 4, the controller is amazing.
It all boils down to exclusives. What exclusives fit more to your tastes?
I also honestly believe that eventhough the PS4 is killing the XB1 almost a year into this generation, once Halo comes out and Gears is announced we will see the gap closing.
I also believe that Microsoft is picking up a lot of steam, woke up, and will be delivering some awesome stuff.