I don't know why there are so many negative reviews. This is a nice add-on. Looks good (I like the choice of paintings or colours as backgrounds), works well. It lacks a few of the customization options that the old Speed Dial add-on (pre FF57) had, but most of that wasn't necessary for most of us anyway.

Personally I wanted something that I could add as the homepage, hence the 4 stars, which is the only reason I swapped to Group Speed Dial. Of course one can always just click the SD(L) button instead of the Add Tab (+) button and that does the same thing.