I picked up both the PS4 and Xbox One. The PS4 as a system is greatly improved over the ps3. The controller alone is amazing. I picked up Knack, Killzone, AC 4, and Lego Marvel. Knack is fun and is your typical action/adventure game from 15 years ago with awesome graphics that give a pixar feel. AC4 and Killzone have been amazing so far, but I haven't really out more than a few hours into them.
For xbox i picked up BF4, COD Ghost, and dead rising 3. Also killer instinct is included but feels unfinished. However it is free. Dead rising alone was the main reason I bought the xbox. With the xbox I cant stand the dashboard. That's probably because I can't stand windows 8 and this uses the same tile system. Installing a game takes about 10-15 mins. Some games you can play mid install but they're limited. With the ps4 I can start playing roughly 15 seconds into an install with some functionality limited too such as mutiplayer.
I play the xbox significantly more, but that is mainly because everyone on my gaming friend list has an xbox versus a dozen or so on PSN. Also i am extremely addicted to achievements over trophies (apprx 140k). I prefer FPS on xbox because of the offset sticks. Right now I prefer the xbox launch games over the PS4. However as a system I prefer the PS4 over the xbox.