Used to be excellent. It's crap useless now. Rated 1 out of 5 stars
This software once was the best session manager on the market. Now it's virtually useless. With FFox updates it now starts to crap out in way less than 2 hours and fails to work in any useful way. You can't save sessions any longer so you basically lose all your newly opened tabs completely.
Bug reports only result in answers that blame Firefox bugs, instead of the creator raising hell with Firefox over the fact that they (according to him) have destroyed his software's functionality.
Like I explained to you, there is likely a problem with your profile (or another add-on) triggering the Firefox bug since the majority of users have no problems. In fact you are the only person complaining of lost sessions every 2 hours. You didn't want to do basic troubleshooting so I can't help you.