Sound quality is stunning! With HD660S (balanced cable) is more enjoyable, detailed and revealing than from Chord Mojo.
Walkman app is responsive and Sony done it very well.
For streaming you need dedicated app, Tidal etc. And here is time for few cons. Android is sluggish (except Walkman app) + no Roon (it needs GL 3.0). Screen is medicore, should be oled instead. Battery life ok/medicore offline, it would be dissapering quickly if wifi is on.
I use wifi only to sync music via syncthing then turning it off.
Materials and body quality is really good.
Overally I'm very happy and enjoy listening music from this little great player.