ability to filter releases into 'new' 'want' 'already have'
ability to delete artists directly from the 'releases' list
better syncing with Discogs and last.fm, who, in my experience, is much more accurate than MusicBrainz...
pull from other sources in addition to amazon. Like CDbaby or even Spotify.
ability to import artists from last.fm based on a minimum number of listens (like.. 5).
a 'blacklist'. for example, I'm not interested in new releases by classical composers. But every time I do a new import from last.fm (to get the other new artists I've been listening to), they are imported back and I have to manually delete them...............every.time.
if an artist is deleted from my last.fm library (or goes below a set minimum of listens) it is also deleted from muspy.