After reading your post yesterday I checked myself and tested some user defined fields, especially list-fields. At first I had the feeling you were right, but then I realized it worked. Synching does not seem to always happen right away. If you make a change either on the client or the server and check the other side right away, the change may not appear immediately.
In the Beta forum Matt described the items that will be synched.
The following are synced:
File value changes
File deletes
File adds (server adds always go to clients, client adds go to server if the server can reach the file)
Playlist additions
Playlist changes (including columns, sorting, etc.)
Television recording schedule
Views are not synched.
I have all my media files on a network share and use the \\server\share notation. I might also transfer the thumbnail and cover art directories to a network share as right now, thumbnails are build in each of the users App Data directory on the server which is quite redundant. Otherwise, so far as I have tested, the new changes are quite impressive.