Rated 4 out of 5 stars
I love this add-on, but I ran into a problem with it when I updated Firefox to version 21. (Version 22 turned out to be incompatible with one of my add-ons so I went down to 21. I don't know if this problem would occur with 22 or not.)
The dialogue window is too tall. This happens on my desktop (large screen) and my laptop. The solution is to autohide the taskbar while I am working with the settings. So the add-on is still usable, just a bit less convenient.