Rated 1 out of 5 stars

Not working for me in FF 19.0a1 (Nightly) 32-bit on win.
Also the keyboard shortcut combination would overlap with other FF restart extensions if you use them concurrently.

Alternatively you can use restartless extension Fresh CSS (working for me), but it also share the size problem with this one (both beyond 100KB), probably both are made from addon development kit.
The one I use is the restart required CSS Reloader, 3.5 KB.