Bookmarks are a nice addition to the filesystem mode. I don't know when they were added but I started looking for that feature only recently.
I was looking for a functionality that would bring me instantly to a location in my directory structure. I am getting tired of drilling down directories every time I start the software. Unfortunately that's not how bookmarks work. When I click a bookmark, the software simply displays photos in that location. This is contrary to the concept of bookmark in file browsers, where clicking a bookmark brings you into the corresponding directory. I wish ASP bookmarks worked the same way, or that a shortcut concept is introduced.
