I'm a recent WinAMP convert and I absolutely love MusicBee. I can't say enough good things about it or express what good things you have done with its creation and support.
I tried to search to see if this exists, so I apologize if this is a duplicate report. I'm running the latest version as of 6/1 (3.0.5996).
I've found myself occasionally frustrated with Auto Playlists. The main thing is that they stop autoing tracks, even if they meet the criteria of the list, if they've ever been removed manually.
E.g. I have an autoplaylist for all songs >= 3 stars. I accidentally manually add a song to my auto-playlist that isn't 3 stars (I don't feel like you should be able to do that either, but not strong enough to call it a bug as I'm sure its a feature for some), realize I've accidentally added it, and then delete it from the playlist. If I later mark that song I deleted as 3 stars, it will not ever be added to my auto-playlist. I have to make a new autoplaylist with the same rules to get my song there.