Rated 5 out of 5 stars
Works great even in combination with Tabberwocky and Tab Scope. I especially like the automatically hiding Groups Bar displaying whenever the mouse moves to the address bar and the hibernation which allows me to keep my tabs for later use without using up memory and without impacting performance on Firefox restart. These three add-ons provide me with the perfect tabs experience.
Thanks for this very useful add-on; I agree that it is worth being included as standard for Firefox.