Spotify vs Apple Music. Which is better and why?

Currently I'm subscribed to Apple Music after my 3-month trial. I'm debating whether I should change to Spotify Premium or stay with Apple Music. Apple Music has caused me technical problems in the past and can be difficult sometimes. I have a 16GB iPhone so I want to save as much storage as possible.

I also can't find Rammstein's Mutter and Sehnsucht albums on Apple Music so when it comes to listening to that I prefer Spotify.

Both are £10/month so price is nothing for me. The only thing I want to know is which takes up less storage and which is more reliable?

I like Spotify better because to me it's way easier to use and find my music. It's easy to make a playlist, save an album, look up artist. ON Apple everything looks nice but is frustrating to use. I can't even explain why but I wouldn't pay for it after my trial ended.

Wouldn't storage depend on what you saved? I don't know what you mean by reliable. I'm not a paid reviewer, this is just my opinion.