A friend has one and brought it out to help us change out a leaf spring on his 5er. I laughed at it. It looked like a cheap Harbor Freight impact gun. I was getting a breaker bar for the 3/4" nuts on the U Bolts and he hit it with the impact gun. It whirled a few seconds and then hit...whirled again and another hit. Did that over and over for about 30 seconds and what do you know....the nut spun right off.
I don't think this one would do a lug nut on a Class C but it truly was amazing in what we were using it for.