Rated 5 out of 5 stars

Very nice. I also appreciated the ability to customize the Firefox button to show only the icon, freeing up additional screen real estate (I use the "Tabs in Titlebar" option). My one (very minor) quibble is that my Tabs didn't take advantage of the additional space right away; I had to toggle the Tabs in Titlebar option off and then on again to get them to adjust to the Firefox button's new width.

This review is for a previous version of the add-on (1.1). 

Thanks.

How do you place your tabs in titlebar?
No problems here when "Tabs Always In Titlebar" extension is used.

https://addons.mozilla.org/addon/tabs-always-in-titlebar/