Great! Rated 5 out of 5 stars

Very fast and very handy! A button for opening tab list would be great though.

This review is for a previous version of the add-on (0.31.3). 

It's been a while, but an optional toolbar button for opening the tab list has been implemented!

Grab the latest version at https://addons.mozilla.org/en-US/firefox/addon/tabby2/versions/