A major drawback of this addon is that it forces you to hide the tabs that are grouped - as far as I'm concerned, this is not really tab grouping, it's more like a "fancy" bookmark sorter, only less functional and more annoying. I couldn't find a way around this problem yet. This is a disadvantage compared to the Chrome tab grouping - where your group appears as a single tab that can be easily expanded and collapsed when you want to show/hide all the tabs belonging to this group.