Rated 5 out of 5 stars
Combined with Tab Mix Plus, this very useful add-on provides me with a very fast and effective Firefox interface without using the Tab bar.
I use Tabs Menu for all of my inter-tab navigation, which is extremely similar to how I previously used Opera without tabs (natively) for years.
Some of the reviews here are incredibly unfair - if you don't see the point, there's no need to offer a low-star rating for something that you don't use.
For me, this add-on is stable and works quite well. I often have 80+ tabs open and there's no hint of a performance issue from the add-on, itself.