I've been using this extension for years now and I gotta say, it's simply the best extension I've ever used. So much software these days is create by UX people that want you to use things a very specific way and if that doesn't fit with your use case/personality, well then you're using it all wrong. Sidebery is the complete opposite, it has a wealth of configuration options that really help you fine tune the experience to get just want you want. For me I really don't like the tree structure options, but I assume many other love it, and with a couple quick option changes both me and those users can be happy.