That webdeveloper toolbar has saved me probably depending on a project a couple of hours or so. especially debugging CSS and making sure its valid
That local html and css thing gets a real workout. The only bad thing is the WAI, 508 Accessibility only being able to check it once like every 1min or so.. I usually edit then have to wait thats one thing i dont like but its not the Extensions fault all of the WAI, 508s do it :mad:
Other than the Adblock extension its probably the most used extension i use 🙂