Album Artist & Artist metadata behaviour in filter view

I have a collection of around 400 CDs hence good filtering/sorting is essential for navigation.

Quite a few of these CDs are compilations, soundtracks or contain collaborations. The artist field correctly lists each artist involved with the track, and the album artist would be 'Various Artists' or the albums main artist.

Songbird had two problems here:
1) Filter view does not allow 'album artist' in the primary (top-left) column
2) 'Album artist' does not default to 'artist' value if the 'album artist' field is blank

This problem can become quite large, for example: you have three artists A, B and C who often collaborate on tracks. Each track artist listing combination becomes an 'Artist' entry in filter view you can get values like: 'A', 'B', 'C', 'A and B', 'A and C', 'A, B and C', 'A, C and B', etc.

As you can see navigation soon becomes unwieldy as you get an artist explosion. In my case there around 100 more artists than album artists!