I am using the 64-bit version too, however I never used theater view in previous versions as it always crashed so I cannot compare.
Do you find that [Album] gets changed to [Album, 1] in the display expression? Is this normal?
For now I am just finding a 'grouping' expression I can live with in the display, but it would be great to get this working properly. I like an artist's albums to appear in chronological order rather than alphabetical, but I don't really want the year displayed ahead of the album name.
FWIW I'm using [Album Artist] heavily for sorting and display, I find this is a great way to manage where albums appear. For example, by renaming the Album Artist to be the name of a compilation, rather than simply using 'Various Artists', this puts it somewhere logical in the view and avoids a huge clump of compilations under V. It also helps me manage loose and orphan tracks - I just set the Album field for odd tracks to 'Miscellaneous', and the Album Artist to 'Various Artists' - unless I have enough of them by a single artist to create a fake album, in which case I just change the Album Artist to the artist's name and hey presto, an instant virtual album called 'Miscellaneous' appears alongside their other work. All the odd tracks disappear into a huge 'Various Artists - Miscellaneous' album. Of course they can still be accessed in other views (eg by Artist/Genre/Playlist) but it keeps my album view uncluttered by orphan tracks with no artwork.