Nobody should be using Fx without this extension, nobody!.. Rated 5 out of 5 stars
... especially those who are concerned about size and 'bloat' of the browser as some buttons can replace extensions, some enhance other extensions. I've quickly collected over 50 buttons and will never use Fx without them!
And, of course, the best forum around with wiki, video tutorials, great search, and other easy useful stuff, including, of course, people - the friendliest place to visit! - no request ever goes unanswered.