Have hung my share of drywall over the years (not as a pro) and always used either hammer and drywall nails or a cordless drill with a bit to drive screws.  This drywall screwdriver really speeds up the process--even for a small room.  It does take a while to get the hang of it, however, because unless you drive the in screw perfectly straight, it won't seat properly and you'll have to back it out and try again.  I'd practice driving a few screws on a scrap of drywall first to get the knack of using it and to adjust the depth setting for your job before beginning work--the screw should be just below the surface of the paper so you don't hit it with a taping knife--if the knife "clicks" on the screw when you go over it, you need to set the depth a little lower.