I thought I'd update mine, as playlist have been made expand & collapse-able and respects multiple nested folders too. yay! Thanks for that Steven btw!
My current wishlist:
1) exportable / save-able / load-able layout files (per tab) plus a way to save & re-apply the 'set displayed field' settings for list/track view
2) simplify / restructure the main MB settings
3) respect MusicBee playlist organisational structures (folders, nested folders & playlists) in itunes.xml export
4) settings.ini - de-couple "library" settings from "player" settings for easier backup/re-loading
I guess the bottom 2 are rather specific... but what else to list on this otherwise perfect music player...