Well designed, simple, and easy to use. Beautifully integrated into the builtin Sidebars. Tabs are automatically arranged in a hierarchical structure and you can fold and unfold a parent item. I've only started using this minutes ago, but I already love this addon!

great, but now i have tree tab, the orignal tab bar is not nececery now, how can i make it disapear?

It's a very big UI flaw that I can't open my bookmarks or history up along side the tree tabs (as they are both stuck in a single sidebar pane). Please complain to Mozilla about this.

Very useful, clean and light weight. Also, an excellent port to the new firefox infrastructure.

This addon does not restore the tree structure when using official default session restore!!!!!

I just had a crash, and what do I get when I restore my session?
All the nested tabs structure is GONE, all tabs are at the same level, and half an hour of work rearranging the tabs into trees disappeared into nothingness. Great way to lose my time.

Oh and I won't even bother recreating it, since Quantum does not support operations with multiple tabs, so I'll have to arrange tabs one by one. Only to lose everything on the next crash.

Oh and there is no "Search tabs" feature for some reason now, so when I need it I need to switch to another vertical tabs addon, use it there, then switch back to this one.

At this point in time, Tree Tabs is a vastly superior addon - it has tab groups, tab search and tab multiselect - all of these features Tree Style Tab lacks.

Found it pretty good but why does it force-enable tab containers? This adds another item to the context menu with no option to disable.

Great extension - allows for really intuitive organization of tabs.

Wonderful!
There used to be a "Search Tabs" feature. Is it possible to bring it back?

The best tree-tabs add-on. Long time user (~5 years) and I like the migration to the web-ext. The only ask for firefox developers is to put an API to hide the old tabs bar so that it can be used by add-ons like TST. Currently I am hiding the tab-bar from the userChrome.css.

Shameless plug: I have written the load-progress-bar add-on to give me a little better idea about the page load progress that I am missing in the new FF57 and I find useful in combination with TST

Can't live without it. One thing that annoys me is that the trees will sometimes randomly collapse by themselves. I've tried changing some settings but it still does it. cheers!

One of the main reasons I choose Firefox - this makes it easy to maintain separate workspaces for different projects, and to keep track of a lot of tabs. Incredibly useful

very unreliable extension at ff 57. At previous versions it worked better.
After initial opening of browser at some of windows it shows "loading" indicator forever. And it's possible to move between tabs with keyboard only at the window. Sometimes it loose list of opened tabs at sidebar, though they are accessible via keyboard.
Also order of tabs is broken sometimes for keyboard.
I tired to struggle with it for 1 month. I give up now.

Very nice, but can't see bookmarks in vertical also. See to Vivaldy layout, two vertical spaces, one for tabs and the other for the bookmarks. If only I could have a shortcut to switch from one to another, at least the lack of seeing both columns at the same time would have less impact.

For years now, trees are easily malfunctioning: many kinds of positional/branch errors or even sticking to a place for no reason.
There should be option for no animation after reordering was requested.
No "unload tree" button exists, not sure if possible.
During last month, a couple of tabs got not clickable, requiring use of keyboard to navigate/close.

10/10 !

to hide the usual tabs, and to hide title bar of TreeStylTab

[your firefox profil folder] /chrome/userChrome.css
--------------------------------------------------------------------
@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");

#tabbrowser-tabs { visibility: collapse !important; }

#sidebar-header {
display: none;
}

Great when juggling multiple tabs. A must have! Easy to use without any issue at all. 5* from a satisfied customer.

Почему после закрытия панели, перестаёт работать инверсия открытия вкладок!!!!!