I've only used this for a short while =after being forced to ditch Firefox and it's pretty good Tree Style Tab extension), but this is absolutely wonderful with it's customisation options, and the groups which add so much clarity and raise this to another level over that old essential FF extension favorite of mine. Creating a "ToDo-list" group, that serves as a reminder right where my eyes go to most when browsing, is perfect for an ADHD person such as myself.