Superb. I'm hugely impressed by amount of features, details and configuration options in this extension. Used Tree Style Tab for months and now Sidebery is my extension of choice.

There is only one (but quite big) issue with usage of this extension, but it's not really fault of the author. Lack of customizable keyboard shortcuts, especially being able to bind switching to next/previous tab to something like CtrL+Q/Ctrl+E. That's an absolute shame for Firefox that it doesn't allow that.

Brilliant! One of the best extensions I've ever used, honestly!
Funny that I had it installed for a year now, along with all the other vertical-tab extensions that I could find, and I didn't really saw what it can do until recently..
It has so many essential features for my productivity, workflow and tab/bookmark management.
Congrats and thank you!!

Really excited to find this extension! Was long term user on Tree Tabs and TST, but this one looks much cooler. And good looking without additional css rules. One flaw, I think white theme should be used by default, it is cool that dark theme also exists.

I'm using it for couple days only, but I like it much more than Tree Style Tab. Love the "Panels".
Finally tab-organizing addon I might be happy with.

The best tab management extension for Firefox among all I've tried thus far (and I've tried a lot of them)! Very flexible, highly customizable and good looking. Very well designed!

The best side tabs ever. It has also container URL rules and User Agent URL rules for containers. Works much faster than any other side tab extension I have ever tried.

The best vertical-tree-style-tab extension (and I have tried a few before). A lot of great options and features, e.g. automatically moving a new tab to a defined panel based on the url pattern. It sometimes crashes after Firefox restarts, but the feature of periodic auto-saving snapshots provides a rescue. Thanks!