A lot of features and options ... but regularly, my tabs lose their group membership (1 tab, 10 tabs, or 40 tabs or more ... I haven't found any obvious logic while issues occur).
Group reliability is the 1th expected feature before coloring or any customization. As a result, experience or feeling is mixed.
Important: no sync enabled, no other conflicting add-on.

Pin tabs are not saved.

First I thought this finally works, on Linux. But frequently my Tabs disappear, new windows being opened instead of the old one, suddenly I have several windows open, and when I transfer tabs from one window to the other, after a while the whole panel where I dropped it into, vanishes. What good is the use of a program that causes you to do lot of work grouping and arranging and sorting, when it frequently causes loss of data? Snapshots have not done the trick for me, it just gets more confusing when it just opens more windows. Updating Firefox causes loss of all tabs. Erasing a part of the browser chronic through Firefox (just one page) causes loss of all tabs. Is not sufficiently integrated in Firefox on Linux in my opinion.

Looking for something much, much simpler to use. All I want to do is to quickly group tabs.

Правила прокси для контейнеров не работают.
А главное - когда включено скрытие вкладок неактивных панелей, при переключении панелей с сотнями вкладок потребление оперативной памяти нарастает безлимитно , пока браузер ( а то и вся система ) не падает из-за недостатка памяти и подкачки

sidebery was better before last update, after the update everything changed and became worse please fix

Would be decent if it wasn't so unbearably buggy. It's constantly failing to move trees around and messing up the tab tree structure.

I really don't get the hype around this extension.
The panel-system can be userfriendly but that's about all. Bookmarks looks a bit friendlier but don't even have a research function - useless when you have thousands of bookmarks. Icons don't load properly too. You can't shut the "Default" panel away...
The settings are just full of features which are unnecessary like scrolling through panel, auto-switch to panel on bookmark click, times in millisecond for smth to open without a click... What the heck? What's even the point of that?

not really anymore useful than default firefox...

I use Sidebery primarily to manage tabs, of which I typically have many open. It seems to do a mediocre job of this. Here are the functions I use and my experience with them:

1. Move tabs within a window. For some reason, Sidebery's drag and drop is terrible. Usually, when I drop the tab on its new position, nothing happens. It typically takes 4 or 5 tries before anything happens. It's definitely easier to use Firefox's tabs than Sidebery's.

2. Tab Organization. Sidebery does support tree structure on the tabs, which allows for some organization. However, it feels awkward to use because of the drag and drop problem. Also, there's no way, as far as I can tell, to mark or label a tab or group of tabs, to make it easy to find later. Overall, a weak implementation.

3. Move tab from one window to another. Again, Sidebery has a problem. After a length of time, Sidebery "forgets" the titles of my windows, and shows only a generic list. To get the titles back, I need to shut down Sidebery and restart it. Unfortunately, this is pretty much every time I need to move tabs, which is fairly often.

4. Search for a tab. I haven't been able to find a way to do this with Sidebery, so I just use the Firefox feature of entering % in the search bar of a new tab.

Many users have given Sidebery 5 stars, despite it being a very mediocre
extension.

PLEASE do not rate this extension highly for no reason!

I wish people wouldn't hand out stars for nothing. It pollutes the Firefox extension ecosystem with misinformation, making it hard to shop for good extensions. This extension is not worthy of 5 stars, or even 3 in my opinion.

Because it still seems to be under development, I gave Sidebery 2 stars, which I think is fair and in fact charitable. If it hasn't improved in the near future, I'll lower this to 1 star, which I think we should all do.

Extremely complicated, but does not even remove the original tab bar from the top of window.

It eats up more space on screen instead of freeing room. So, what is it good for?