Looks Good & Conserves Screen Real-Estate Rated 5 out of 5 stars

Looks good, gives you extra screen real-estate, reduces toolbar space. I use the extra space to add more toolbars, more toolbar buttons (via the "Toolbar Buttons" extension (https://addons.mozilla.org/en-US/firefox/addon/2377)) which I organize with flexible spaces so I can group like buttons together. And there a (relatively) new options addon (https://addons.mozilla.org/en-US/firefox/addon/6969) that allows you to keep the compact size but modify the look-and-feel.

This review is for a previous version of the add-on (3.0.9).