Rdio had some really creative curation features. The "What's Hot" feature, which was a current hits list of what your friends like and are listening to was really amazing.
Their auto-play radio feature (it would start playing similar music based on what you just finished listening to) was great.
And lastly their "adventurous" slider, which allowed the radio station song search to land somewhere in the spectrum of just songs in your collection to new stuff you didn't have but was in some way related to the current radio station being played....man.....this feature alone was worth the whole subscription in my opinion.
The Spotify equivalent of "For You" is where I'm having the most luck. Maybe I'll give Apple another go.
Funnily enough, it has recommended a lot of British Isles trad/folk to me, (and also Québécois, for some reason) most of which is OK but some of which is really interesting. It's found several long medieval ballads, which I would have thought was far too niche to recommend.
I can't think of anything that Apple Music is great for, which is not very Apple-like.
Obviously there's a lot of personal preference here. Add in that Google has a TON of info on me, way more than Spotify could ever have, and it's almost not a fair comparison. I should mention that I left Spotify because they have a 10,000-songs limit on how many songs you can save, even with a paid account, and that was absolutely absurd to me- IIRC, Google lets you actually upload more tracks than Spotify would let you save.
(To be fair, Pandora is better than the others, but dependent on genre. It does really well with classical music. With lots of electronica/electronica related music -- very annoying.)