I'm not sure why, but MM and iTunes (>10.7) both do this:

The list of columns should be customizeable to the library AND the playlists.

If I make a playlist and put "Tempo" in it (for example), then Tempo is one of the columns in the main library listing. I don't want that. Likewise, my main library window might benefit from time and filesize, but my gym playlist doesn't need that.

Also, I've noticed that smart playlists will permit re-ordering the columns, and those orders will stay the same, independent of the columns in a dumb playlist or indeed the library view itself.

Would it be possible to make each tab, playlist and/or node columns customizable seperately from your other tabs, playlist and nodes? For instance if I have a playlist for BPMs I'd like to have the Title, Artist and BPM columns showing for that specific playlist while keeping my playlist for three star songs with different columns (title, artist, ranking).

Thanks.