Terrible add-on. Used it for just 2 days. On 3rd day, all my saved tabs were gone. Missing. Poof. No explanation. Not simple at all. More like complicated. Avoid at all cost.

After year of ordinary usage just wiped all my tabs and backups too!

Worst. Extension. Ever. Arbitrarily deletes tabs with no warning and no option for recovery.

100% CPU usage

It's good extension but when it has big bug: sometimes tabs in one of the group are duplicated during browser restart.
Update: very stupid and annoying bug, I did reopened the browser 6-7 times and now I have 100 tabs in my Work group. It's so buggy. Can't use it anymore.

Was very exited to use this extension, but sadly it has been extremely buggy. Tab groups break as soon as the browser is closed and opened. The whole plugin breaks and I had to manually disable and reenable the plugin to get it working, only for it to break when restarting the browser.

I LOST ALL OF MY TABS SAVED ON STG GROUPS!!! AFTER SHOW THIS MSG... :((

''
Database error in Simple Tab Groups
Unfortunately, an error occurred while reading data from the STG addon from the Firefox database. At the moment, the addon is stopped. To resume the add-on, do the following:
Restart Firefox Browser (for Linux and Mac OS with process termination)
If you see this window again, try reinstalling the addon:

Remove STG Addon
Restart Firefox Browser
Install STG Addon
Restore the latest STG addon data backup located in the Firefox downloads folder "STG-backups".
You can restore backup in addon settings
''

It is really not convenient. I cannot use multiple groups at once, I cannot use pages that are not grouped. Group switching is very slow, 3 clicks are needed compared to Chrome's 1 click show/hide feature. The menu system is VERY un-intuitive.

This extensions seems nice at first glance, but after using this extension for a while, I view it as being broken. When you open Firefox and you have a lot of tabs already open, you sometime get tab duplication. A lot of the tabs gets duplicated. It makes Firefox very slow to startup. It is unusable in Linux. When you open Firefox, the tabs load without any end. It loads forever and Firefox is unresponsive. So to summarize:

1) Tabs duplication bug
2) Very slow Firefox startup
3) Unusable in Linux, it simply does not work in Linux

I can't rate this extension more than 1.

Cumbersome to use. Not intuitive. I thought maybe I could take a few open tabs out of several and group them. Sure, but now the rest of the tabs are gone unless I also group them. Essentially if you want to group, you have to group everything into groups or you're accessing your non-grouped tabs through a little dropdown. If that's not the case, it wasn't intuitive enough to figure out otherwise or would be efficient to use.

The idea is nice, but I feel misled. It said it "works like chrome's" but the one in chrome collapses and opens with a simple click. I feel like once I have a tab in a group I better not hope I can access it ever again. Clicking on the link just make the page refresh. Again, not cool to claim it's "like chromes" when it really isn't

Put all my tabs into a group, restarted firefox, the group no longer exists.

STAY AWAY IF YOU WANT TO KEEP YOUR TABS!!!

I did not install this extension because once I saw how much data it collected and what it wanted access to, I was quick not to allow it. Why does it need access to recently closed tabs, access to download files, read all website data? C'mon... this was one of the only tab grouping extensions I would have use too...

Private mode is NOT SUPPORTED. What a bummer!

The absolute worst thing happened to me! I tried to open an old tab in a group I that's never been opened for months, I checked Task Manager and Firefox went from 5gb memory usage to over 20gb and it just kept increasing until my PC stops responding. This memory bs happened everytime I try to open Firefox, so I had to uninstall Firefox and lost everything.

Nothing 'simple' about this add-on. Confusing and over-engineered. Name change is needed...;)

A major drawback of this addon is that it forces you to hide the tabs that are grouped - as far as I'm concerned, this is not really tab grouping, it's more like a "fancy" bookmark sorter, only less functional and more annoying. I couldn't find a way around this problem yet. This is a disadvantage compared to the Chrome tab grouping - where your group appears as a single tab that can be easily expanded and collapsed when you want to show/hide all the tabs belonging to this group.