I've been using this for quite a few months, and the developer has added some very nice features during that time. Organisation of tabs is a breeze with this thing.

I can select tabs without loading them, put tabs into general organisational groups and trees under each other, close and move lots of tabs at once, and so on. The tabs are also displayed pretty compactly by default, and additional information (such as whether or not a tab is loaded) is well conveyed. A number of these features cannot be found in some of the more well known tree-like tab extensions, which is why I use this one.