I've found two bugs with the Applescript support, valid in the latest version, 18.104.22.168:
1. the "artwork" returned for the "current track" is always null. It used to work before, but I don't exactly in which version it stopped working:
2. the "player position" property does not return an up-to-date value from Spotify. It seems to keep returning the same old value, instead of the value currently shown in Spotify. Spotify always returned "111" seconds , even though the song was playing:
On the other hand, iTunes behaves as expected, returning an up-to-date value:
3. As a bonus, it would be nice and if the "starred" property on a "Spotify Track" were made writeable.