"Smart" is an understatement
this thing is awesome. perfect combination of a grigri and a atc guide. locks off quick but can be disabled with a quick flick on the thumb lever for yarding out rope to the leader. the longer release lever give you more control than a gri, and whoever wrote the reviews about it being a horrible rappel device is a bonafide idiot, although its a slightly unnatural technique, it offers more control of speed and still auto-locks for when you've got to retrieve that stubborn piece of gear. uber versatile!!!