The problem here is that people are looking at this from the perspective of how things worked in the tree. It takes a bit of lateral thinking and a little bit of tweaking of your view schemes but it actually works a lot better once you have done this. Example - using the new library I have tweaked my Artist Album view scheme to create a directory style view (don't try it at the moment as it doesn't work. should be fixed tomorrow). The scheme is set like this Album Artist(grouped at level 3 set to show individual items, Album Artist (no grouping), Album. This produces a four column view. The first column has grouped letters A-C, D-F etc, the second column shows A-Z, the third, Artists, the last Albums. To find a particular Album Click the group of the Artist eg Audioslave you click A-C, the second column changes to show A B C, the third shows all artists A-C the forth their albums. Click on A in the 2nd, 3rd shows all A Artists 4th their albums, click Audioslave in the 3rd, 4th shows Audioslave. It is actually very intuitive, much more so than the tree once you think it through.
Wait until later when the bugs hav been ironed out and then try and approach it with a completely open mind thinking about how you can work in this environment and forgetting there ever was a tree and believe me, pretty soon you will be saying "Tree, what tree?"
Adam