Well the title is pretty much self-explanatory. I've got a brand new iPhone 6 that should handle Spotify with ease (even the 5S with the A7 should be included here), yet auto-scrolling (tap the upper part of the screen) in a playlist with more than 100-200 tracks will create a stutter/lag-fest 101. You should preferably scroll past 100-150 tracks and then press the auto-scroll to see it. I assume I'm not alone experiencing this, but I'd love to hear if you've noticed it too. It even makes the 4*4 album art dissapear which is above the playlist. A bug I guess?
Spotify is honestly not exactly a smooth experience and the app itself doesn't really feature a lot gaussian blur or flashy animations to even justify that. If anything it seems poorly coded to be honest.
Auto-scrolling in playlist with 15-20 tracks is fine, since I assume it won't have to "tax" or load as much, but apart from that it runs terrible.