RE: who really uses one of these?
I am not sure about GA. Below is the paragraph from our Regs. I would read this to say that it is illegal. Seems like it would take the skill out of the challenge anyway.
Primitive Weapons: Legal weapons during primitive weapons season include crossbows (scopes legal), bow and arrow, and muzzleloading firearms. Muzzleloader hunters must use iron sights or peep sights (fiber-optic material is OK) during primitive weapons season. Scopes and other optical sighting devices may not be used during the primtive weapons deer season.