It's quick in normal use, but does get choppy when downloading a bunch of stuff. The UI is pretty nice, if a bit simple and dull. Some options are poorly conveyed or outright missing (like Eel mentioned). Like, say you want to manually delete video captures. The capture library you get to after pressing 'share' doesn't let you delete videos. Instead you have to go to the home menu > profile > captures > and there's another capture library where you can delete videos. Or that games run in the background, so you can watch netflix as a match is loading and double tap home to switch between programs.
I think the Xbox One UI is sleeker and gives off a better illusion of newness, especially with snap. But there's a surprising amount of parity between the two this time. Both controllers are good, both UIs are nice and have comparable features, etc. imo, neither seems to have a distinct advantage or disadvantage. PS3 always felt dated/older compared to the 360. In some areas PS4 will still feel dated, but not in all areas.
Oh, and the touchpad doesn't seem integrated into the UI at all. Unless I'm mistaken, you can't even use the touchpad on the web browser. Would be nice to swipe though the games list and whatnot.
Got my first system freeze, was downloading updates for Warframe and the shit just hard locked, had to pull the plug to reboot
then it chastised me for unplugging, like i had a fucking choice
looks like this is probably gonna be a thing now for the new consoles
welcome to PC gaming, console owners
Apparently Warframe is problematic because it updates on its own server. Blacklight Retribution seems to be similar and that didn't work online at all. Offline bot matches ran poorly and had bad tearing. Both felt like straight up PC games dumped onto the PS4, for better or worse.