The base problem for "looking" short clipped or hairless has to do with the colour of one's hair. Dark hair against light coloured skin, even quite tanned skin, will show more. I.E. the O crop while clearly very short will still show and reveal where the unwanted spaces are. A shaved head conceals that problem, at least for a bit. In all circumstances there's up keep. Unless, of course, you want to cover your balding spots with excess hair....