i dont know about the technical differences, but as far as the size goes, i cant really feel that much of a difference; *if anything, id say that the wiz7 is a little more round feeling. * the thing that really gets me is the nasty stuff on the back of the rg7 necks -- im all about raw wood or very light
tung oil. * but as far as size, maybe my perception is off, *cuz i dont know the actual specs.