Hi Guys!
I recently switched from Apple Music to Deezer and missed, in my opinion, very useful feature - possibility of viewing family members music library (playlists, favorite songs, recently played history and etc.) I had this feature in Apple Music and it was very useful. Now there is no such possibility in Deezer.
In addition, you can synchronize your phone contacts, google, FB accounts with Apple Music and request access to your friends library with a same purpose - to see what they are listening to (if they use Apple Music of course).
Finally, for new users, it would be great having possibility of importing previous Music Streaming service playlists to Deezer. This is something that current Music Streaming services don't offer, so could be competitive advantage, if it is possible obviously.
Hope you find these features useful.