I've been using it for more than a decade, horizontal tabs are unusable. Now retiring VTR in favour of builtin feature of Fx >136. Thanks for your service!

Хороша річ для повноекранного режиму, а так useless. У FF бідовий фулскрін: кермова панель при появі змінює розмір сторінки, невже не можна було зробити як в IE? -- поверх контенту?! така поведінка панелі дратує, а з вертикальними вкладками панель не потрібна. Дизайн вкладок слабуватий, ідеально було би додати значкове відображення для усіх вкладок, регулювання розміру значків і зменшення бокової панелі, хоча не певен що FF дозволяє міняти цей розмір довільно.

Hate how it looks :(

I really like this add-on, but now I have a page that tells me: "You cannot use developer tools with this page. Please close them and refresh." …if the sidebar is toggled on. Are there any workarounds?

Omg this is SO COOL!!! What a slim and revamped Firefox does this give!!
If there would be something to add, I can only wish for a "merge" or "blend" window controls into the meny bar, so to still be able to minimize the window when all the "hidden" options are on.

Excellent add-on, thanks for the hard work! You cannot set font size and spacing, but the feather theme is very condensed and I like that. I hope this is going to be available on Chrome at some point.
A couple of suggestions:
1) remove the dividers among items, they add weight and are not needed. UI will look better without.
2) I like to keep the panel on the right hand side. When many tabs are opened and a scroll bar appears, it's quite difficult to hit the delete icon. I suggest to make the target area larger.

Good, and (unlike some others)
has a close button for the tabs and
an option menu.
But, settings can't be changed in Private mode
and there's no simple button to switch
between bright/dark mode..

Been using this for a week or so. Very nice. Would love if you could add Firefox container options to the context menu when you right click on a tab, i.e., "open in another container...". Thanks!

This is very useful. I hide the top tab bar with a userChrome hack and just use this addon. I like the compactness of the tab bar.
What I miss is support for container tabs - VTR doesn't show the container color and doesn't have the menu to move tabs into containers.