I used PZDb for over a year. The shortcoming with it, (as with all CMSs) is first teaching it what goes with what. PZDb does, indeed, have a system where you can set flags that group materials, poses, and items together, but it may or may not work automatically. It depends on a number of factors including how the various files are named.

With the appearance of the PP2012 library, I really don't find an external library that much more helpful... especially if you do a little re-arranging/renaming of the content folders yourself. And don't forget the "Favorites" area. Bagginsbill has accomplished real magic there.