If it's running it's a fine app.
But every few days when opening the app it's just stuck for about 5 Minutes before responding to any command (i.e.: play). Very, very annoying.
It's like doing some indexing in the background and waiting for that to finish.
It's way better on the 950XL than on the 930, but that may only be the faster CPU.

I have only one playlist, but a lot of saved artists and albums.  
This behaviour is present since the first Win10 version.

I already did a complete reset (of the phone) starting without backup, after that

the first day it was working fine and fast, on the second day in the morning just stuck for about 5 Minutes.

Please fix as soon as possible and feel free to ask any questions.

Windows 10 Mobile (10.0.14372.0)

Spotify App: 5.2.3.0