Rated 4 out of 5 stars
Many small details show that a lot of thought went into this add-on. I particularly liked the ability to muck about with the stylesheet from within the preference menu itself, or even to import one, and the ability to to export the output to another file was also nice.
An option I would very much like to see added would be some way to specify the format of the titles. The current behavior is to show the entire breadcrumb path of a sub-folder (eg, "Writing > Fiction > Poetry"). An option to show only the subfolder's name without the preceding breadcrumb trail (eg, "Poetry") would be nice, especially since the parent folder will so often have some dreadfully ugly name like "Bookmarks Toolbar." :)
I had a problem with the context menu link on Linux Ubuntu 8.04 with Firefox 3.6.13. The link reading "My Bookmarks Layout" does show up in the context menu, but its submenus won't display. There's a funny little line that shows up when you mouse over the link, which makes it look as if *something* is trying to happen, but the actual submenu doesn't appear. I tried it out on a clean profile just to make sure that the problem wasn't with another add-on and had the same problem, so I suspect that something could use a bit of fixing there.