In my experience with both (currently subscribed to both) Spotify is quicker to extrapolate from less information, and Apple is more patient and observes longer-term patterns. They both eventually get to my tastes, but I can more-rapidly alter the primary genres of my Daily Playlists on Spotify than I can of the various weekly playlists on Apple Music.

I like each for its own reasons, though if I had to choose one forever, I’d probably pick Apple, but it wouldn’t be by a landslide. :)

Similar, and recently. Apple Music has some wild ideas of what music I'd like to hear, and if one of my kids plays a song on my account I'm in for the extra special treat of hearing a lot of their music for a while. Even constantly telling Music that I don't like the songs. Spotify has been nearly magic in its ability to predict what I would enjoy listening to.

This, and AM had a horrible penchant to get “stuck” on certain genres/artists, and focus primarily on what I already liked, even when moving to other genres. I did successfully find some new songs I liked, but Spotify had a much better hit/miss ratio, especially with foreign and indie bands.