Being a very long time free Spotify user, I can't believe that I'm very likely going to buy a yearly sub to Apple Music now my 3 month trial is up; despite iTunes being a total piece of garbage. The big kickers for me are Spotify's list view text being absurdly big; a complete lack of editing the track info and no ability to add other columns, like Year, Genre, etc.
If you could take Apple Music's superior music catalogue (in my case, anyway) Mini Mode, the ability add extra data columns and the white UI, and combine it with Spotify's far superior search and artist and album hyper-linking and superior personalisation (again, in my case) you'd have the best music service in the goddamned universe. lol. Why can't we have that :(