Roofing shingle replacement: Hand nailing vs nail-gun
I believe with a properly adjusted gun better results or at least more consistent results are possible. I always carry a hammer to set nails that hit a knot but I don't think it is cheaping out. In 20 years watch him starting to have have to wear a band on his elbow and possibly surgery from swinging a hammer. Full head nails available today are the same just in a rack or tape to fit the gun. I use my coil nailer and have not had any problems.