when i used it with a splitter into the controlle rit was awful.
i am used to decent sound quality though and was using highly regarded headphones (not crappy gaming headsets which are all about form over function).
in terms of SQ
optical > USB > DS4
there isn't much difference between optical and USB apart from the fact one is stereo only, in terms of quality
the DS4 uses bluetooth to communicate with the console, it will be cheap parts too, not apt-x or anything near that
it is good enough for voice comms, think old bluetooth headsets, but there is a reason why apt-x was invented and is now recomended for anyone looking for quality over bluetooth.
i wouldn't recommend running game sounds through a ds4 at all, voice chat only and your fine, i could hear crackles, hisses and pops, but a decent set of headphones will show them up a lot more than a poor one. if i had to rate them i would say;
optical - 10/10
USB - 9/10
DS4 - 4/10
it is that bad for game sounds
i would recommend using a cheap USB headset if you want to run game sounds through them over the ds4 any day
something like this only costs 80p and is a better solution
http://www.amazon.co.uk/Speaker-Aud...mputers_2?ie=UTF8&refRID=1DXHAKW1894MQ4MMWS0X