I haven't left Firefox because of this extension.

marvelous

This is the single add-on that is keeping me on Firefox. Kept me here for years and I can't live without it :)

Can't imagine using Firefox without this add-on. Great work!

So good I even remove the default tabs with some CSS tweaks.
Those complaining of lag you should try something like 'Auto Tab Discard' to unload tabs from memory if you want to have hundreds open for some reason.

after using ~one mouth going between tabs is lagging so it`s impossible to use

Thank you for this.
Best tool to arrange tabs imo.