Well Maintained, and works great Rated 5 out of 5 stars
I was surprised to see AMO showing an average rating of only '4 stars' for this wonderful toolbar. And you can configure your toolbar on-the-fly, just by including the 'customize' button right on the bar on the bar! With a wide screen, like mine, you can fit all kinds of great anti-ad, cache speedup, security, and menu items from other menus into single-clicky icons or text buttons
I like working FAST. There are a lot of menu items which I'd like to get done with ONE "drag and click", rather than two (using the Menubar, you spend one drag and click activating the Menu. The you do it again to choosing and activating a specific Menu Item. Twice as much work !!).
In any case, the "downgrade" of the average rating comes from two reviewers. One person may have been correct, at that time, about "issues with Beta 4.7", even though I feel that it's NOT NICE to punish with "Star takeaways when you're using an Alpha or Beta Pre-Release version. In any case, his self-proclaimed nitpick is gone and fixed, long ago: As of this date I'm using Firefox 7.0a2 (Aurora channel), and prefbar is perfect.
The other reviewer, giving two stars for a feature which has already been restored AND documented, needs to come back and remove those posts. The Developer even posted comprehensive instructions here, but "someone" doesn't seem to have noticed. NOT NICE!
For me, this is one of about 10 add-ons worthy of all 5 stars, it's enormously beneficial for my use of FireFox.