I've converted at least 5 people from AM to Spotify once they realized things like the social features like collaborative playlists, artists created playlists, following your friends to see their playlists and what they're listening to and they all tend to say the discovery/radio is much better although I think Pandoras blows it away. The UX is constantly in flux and it's different between OS's (only the desktop has 90% of the social features) and they keep nixing good features (mostly social, I guess due to EU regulations) which is frustrating.
Last year they updated it and removed the Android widget completely - we absolutely revolted blasting them with 1 star reviews, etc. They timed it with the launch of their India service so I have this theory that they knew they'd lose a bit of customers (they had no idea how many Android use widgets apparently) and negative reviews would come in but replace them with revenue/reviews from India which knocked their stars right back up.
Literally same day. I don't like the company because of things like that but it's still IMO the best music service. I'm using Tidal as well for its hifi/masters now.