Great Concept, Not So Great Execution Rated 3 out of 5 stars
This add-on was the first one of it's kind that I've used.
It shortens the add-on bar, increasing Firefox's webpage area and functionality. It also integrates Download Statusbar into it's minimalistic appearance.
Unfortunately, after retesting it for 10min I found that many bugs remain still.
As mentioned by No Nothing, the bar doesn't always stay collapsed and it always pops back up on changing tabs.
I've also found that, when there are downloads running on Download Statusbar and the find text bar (Ctrl+F) is active, the bars become messy, with an empty bar at the bottom and Barlesque unintentionaly merging into the find bar.
I recommend using Minimize Addon-Bar instead.