It loses your tabs! Beware of this possiblity. It was last updated 2 years ago so may be incompatible with the latest firefox.

Used to be good. Now on occasion when click 'bring all tabs into onetab', all tabs are closed but are not brought into onetab - ie they are gone, gone, gone. An extension of this type has to be consistently reliable, else it's worse than useless. They don't seem to be updating it, so I guess it's dead.

I have been using this Add-on for years, I am a Tab monster and I am always letting them get out of control. One click condense, once there I will often times right click in the history to selectively reopen the tabs (in a new tab) thus saving my history in order of appearance.

Love it! Thanks!
But, how to start a new tab group?! -> Just found an easy solution: just "import URLs" a new url with a description. See in "Export" on how to format it. Any imported url will be added to your list. Don't include all ;-)

Almost useless. Does not save "new tabs" and pages like "about:config". Reverses the order of tabs and does not allow to save tabs in file on disk.