[weberer]

The biggest benefit I've seen is that it automatically hides the old tab bar at the top. Before that, you had to dig into some hidden profile directory and modify some userchrome CSS file and modify the CSS directly hoping it would work.

[dns_snek]

I use this method personally and it works great on GNOME and KDE. First set `toolkit.legacyUserProfileCustomizations.stylesheets` to true in `about:config` then find your profile directory in `about:profiles`.

    cd $FIREFOX_PROFILE_DIR
    cd chrome
    git clone https://github.com/MrOtherGuy/firefox-csshacks
    touch userChrome.css

The contents of userChrome.css should be:

    @import url('firefox-csshacks/chrome/hide_tabs_toolbar.css');
    @import url('firefox-csshacks/chrome/window_control_placeholder_support.css');

Then restart the browser. If anything breaks the repository will likely be updated soon and you just have to pull the changes.