This has quickly become one of my must-have addons, I tend to not close tabs and the "switch to" feature of the AwesomeBar only works when it wants to, so I end up opening multiple of the same page. The ability to easily spot duplicate tabs, and also closing tabs more efficiently were what I looked for when I found this addon.

There seems to be a bug with the addon though. I can't find a way to save settings, there is no save button except for the one for CSS, and when I close the settings and open them back up, the changes are not saved.