I've got a ps4 and xbox one and a 4k tv and while I can see the ps4 is often sharper I don't care that much about the difference. I'm fairly close to the tv too and its 49" which while not huge is a reasonable size at least here in the uk. I'd probably like the option on ps4 to render at 900p just to make the 30fps frame rate more rock solid. To get to 60fps will need some sacrifices in graphic detail and I think has been shown consumers are enticed by great graphics.
I love the feel of 60fps gaming though but with modern tv's with their input lag it just doesn't feel the same as playing 60fps games on a CRT tv which were super smooth. My tv has a reasonable input lag of 31ms and the best can be as low as 21 and the worst over 100ms but CRT tv's had 0ms lag unless they were premium models with 100/120hz output or high res tubes with upscaling.
