Puntuado con 4 de 5 estrellas
It's a good alternative for restartless CSS Refresh (non working for me).
The main drawback is the size beyond 100KB, it's probably made from an addon development kit. The keyboard shortcut, hijacks F6 of FF for focusing the adress bar, but you can avoid that as it's configurable.
Alternatively you can use the restart required CSS Reloader extension, only 3,5 KB.
(FF 19.0a1 32-bit on win after editing FF maxversion parameter into install.rdf file)