Excellent Add-on for Firefox 4 Rated 4 out of 5 stars
This add-on complements Firefox 4's slim user interface. There is, however, a slight suggestion for improvement.
@Gomita: Consider increasing the the area under which the toolbar automatically pops up to about 8 pixels.
As it is now, when the user chooses 'Automatically Hide' in normal mode, there is only one pixel of area sensitive to mouse hovering.
This it makes the option less useful especially when the firefox window is not maximized (restored).
When this issue is addressed, this add-on will get a perfect rating.