Works great on both Firefox and Chrome - allows me to swiftly transition between browser environments. The cloud sync is very useful when setting up my browsing environment on a new machine, which I do often. I also just like how it's really minimalist. You can par it down to just big button-icons if you want to, with or without text. It's fast and easy to move between tabs and works on touch screens because of the size. Oh also it works well with the latest version of Firefox!
