Question about Spotify and caching

I am not sure if I am hallucinating this or not but the other night I was in clurb dj’ing with a friend. We were using a mixture of Spotify with a 4G connection and iTunes and I was fairly certain that the tunes from my Spotify playlists (That I use all the time) were loading much more quicker than hers (That I have never played before). Do we have confirmation of some kind of caching in action or was it just the rugs messing with my time perception.