This is not Fast Dial, but Fast Dial is sadly no longer supported. Why not 5 stars? Because it doesn't load on Firefox start, you need to wait about 30 seconds for Group Speed Dial to load, pretty long right? Sometimes dials go missing during normal browsing and you need to wait for them again. Fix this (and don't screw up anything else) and I will rate 5 stars.

Other thing I don't really like is creating new account so you can have your dials synchronized. In Fast Dial they were bookmarks so you only needed Firefox account for this.