Is the PS4 any good?... hmmm....
Well, the hardware is pretty good for the money.
The CPU performance is about the same as the Xbox One's, but the APU has a bit larger GPU, and there's a nice big pool of fast memory. Games tend to feel a little CPU bottlenecked (which is the same on the Xbox One), but play pretty smoothly overall. The controller is excellent. Vita remote play has too much latency, and the WiFi chip is kinda cheap....
Overall, I'm happy with what you get for the money on hardware.
The OS is in it's early stages still. It's laid out well, but there's no folders, and some basic features like DLNA are still in development. App maturity isn't so good either, with stuff like HBO Go still not available. Overall, it's a pretty horrible media player at the moment. I can make a long list of devices that are better.
First party games have been sorta crap. Killzone looked nice, but that's about the only good thing I can say. Knack was pretty lame. Infamous felt similar to previous Infamous games in a lot of ways, and still suffers from somewhat mediocre combat...
For 3rd party stuff, it's also boring. FF14 runs on the system pretty well, but you'd be better suited using a PC for that one... but, if you need to use PS4, it's fine. 3rd party AAA games run well on the system, but are starting to suffer from "parity", where devs will intentionally match performance with the Xbox One.
We'll get another wave of games here soon, for the holidays, but thus far it's been pretty darn boring on both the Xbox One and PS4 fronts....
I'd say overall my answer to "Is the PS4 good?" is:
Not yet.