I am struggling to think of a place I could have used this in recent memory. To twist 12 awg wire must take at least an inch bare, if not a little more, then you have to have access with both hands. Plenty of excess wire and plenty of room to work, I dont recall having those luxuries to often.
My wife's Yukon had a bad connector under the drivers seat. Probably had 14 or 16 wires in it. It was all I could do to have one hand under there with the crimper holding the connected and still being able to see anything. Of course I was doing a head stand in the back seat. That is the kind of BS I am lucky enough to work on, never any gravy.