Great stuff, thank you!

This hide my sick of tab on the top of the screen to side bar! Really useful! Thanks for creating this stuff!

Please add the ability to see tabs of all firefox windows ))

I prefer this lightweight addon compared to tree-style-tab and sideberry. Just the right amount of features and customization. Congrats on a great extension. I hope you don't bloat it!

Pretty good Add-on , no changes required

Just like Tree Style Tabs, minus the Trees and plus the containers.

This is a must-have extension! Tabs should be vertical by default because it makes having many tabs more readable in a single-window.

One small request: retain the zoom level and tree expansion when re-opening Container Tabs or closing the Sidebar.

This extension could save some space by:
(1) limiting text-wrapping to a certain number of lines,
(2) expanding the area that says "drag a tab here to pin it" only when dragging,
(3) having only collapsed groups show the category titlebar/icon while making the colored strip next to any tab collapse its group when clicked, and
(4) facilitating a new-tab and close-tab with separate action buttons that work even when Sidebar is closed.

This add-on would be great if it followed the theme currently applied to Firefox. I really dislike the jet-black look in contrast to Firefox's default light theme.

This extension does exactly what was described the way I wanted from it. Thanks.
Though it would be handy if I could select multiple tabs and move them all into another container or delete them.

I just wish this add-on knew about container hiding.

It is a functionally beautiful add-on. It does all I expected it to do. However, I noticed a big hit on Firefox performance when it is enabled and there are a lot of tabs open (which is why I needed it in the first place).
In summary, I had to disable it and switched to "Tab sidebar", which is not as feature packed, but keeps my Firefox quick.

Great extensions, works perfectly...
...but i just noticed that your extension have low activity always on background, even when sidebar is not even open. Firefox own task manager show "low (0.4)" all the time. I am aware that all extensions are sometimes active on background, but not all the time.

Its a good start. I like the extension but not so much to give 5 stars just yet. But still great work. To suggestions Mordynak wrote I'd add few below:
1) Customizing the containers as you'd like. At the moment there are only 5 categories. I'd like to modify or remove some them completely and replaced with my own.
2) Possibility to hide tabs in containers from the browser's tab bar. Possibility to show only these which are inside of focused container.

Cheers