I bought mine on recommendation from people on a bike forum who recommended it for undoing front sprocket retaining nuts on my Busa.
There's no other way of undoing this nut without a compressor.
I also used it for undoing a 34mm clutch centre nut on my current bike. Because the clutch spins, normally you'd have to put the engine in gear and then lock the rear wheel somehow (putting undue strain on the drive train) in order to undo this bolt. Its a real PITA to undo.
The cheepo clarke impact driver gets the nut undone without the need to do any of this, no sweating, no hassle, Brilliant!
[EDIT] It shouldnt do any damage to the nuts if you use the right size socket. Its only doing what the tyre shops air tool does when they remove the bolts.