Very useful addon. Some notes;
Can be very sluggy under heavy use.
When switching group, opening existing tab group in new blank window forced reloads all tab in the group, which is bit annoying.

Edit: This is the review from same guy that has send the bug report and got response by email. Thanks for replying!

Edit 2024/01/05;
It seems like STG conflicting with Foxytab addon. Disabling Foxytab make STGs editing like closing/moving tabs significantly faster and there is no crush.

I just love, love, love the ability to put all my different research/interests/archive into groups.

It's awesome ! Really helps to manage >100tabs. Thank you so much!

I love it. I'm using it to create different areas for my work env. I have stuff to read, docs to follow, and current worspace etc. This extension is excellent, super stable so far.

Exactly what I was looking for. Allows you to load a group of tabs in the current window and flip between groups without any problems. I only wish there was an visual way to identify which groups are currently loaded without clicking on the menu button.

this is very useful in theory and most of the time, but especially recently my tabs have been jumping groups, which kind of defeats the purpose. additionally, I've noticed that when closing my active tab the extension often switches groups automatically, which is annoying.

I had quite some tab groups, but they were suddenly empty, so better keep your bookmarks organized.

Closing a window removes all of the tabs from the tab group. Restore previous session is already enabled. I'm not sure how to trust this extension, though I want to like it.

I don't know what happened, but from some moment extension started to hide my tabs - I couldn't find an option to disable this behavior, it is very annoying. I want all my tabs displayed in a row, not to open a list every time and search from there.

After some time this behavior is back, with v4.5.1 (FF 79)

The extension is great, but I'm sitting on 4.2.2 because in versions 4.3.* the recovery functionality ("Restore") is broken, as a result of which after recovery I have duplicated groups. I ask you to return the old functionality, i.e. such: "Warning! Restoring from backup will ERASE all existing settings and groups!". This is the classic recovery from backups. Or in the new functionality, please make the checkbox "ERASE all existing settings and groups".

Very easy to use. Simplifies my Life!
Would be nice to have automatic backups as I close Firefox. Until now it´s only possible to have daily backups, which are generated when I´m starting Firefox. I don´t think that this is a smart solution, because these backups are not including the tabs I´m opening in the session.

Afer one of last updates regex for catching tabs stopped working correctly. I have some site inside my corporate network with address https://somesite/. I used "https://somesite/" filter to catch tabs with this site and it worked until some recent update. Now the only expression, that works, is "somesite", witch catches all sites with "somesite" in URL. Escaping "/" also doesn't work. It appears that any expression, that doesn't match examples in help tooltip, doesn't work (Firefox 70.0, addon version 4.2.2).
Update: Regex https?\://somesite/? works only when I open link to "somesite" in new tab inside browser. When I enter adress maually or open link from external app (i.e. Thunderbird), it doesn't work.