I'm using both Spotify and Deezer. Both Premium accounts with the highest sound quality settings on both apps. Deezer sounds much much better than Spotify on "extreme" settings.
When is Spotify going to improve their sound quality ? You're bitrate is OGG wich is really bad and far from 320kbps.
The only reason i have Spotify Premium is because there isnt a Deezer app on the Playstation 4