Wall hung bathroom furniture tends to make your bathroom look larger and leaves the floor easier to keep clean. Wall hung vanity units are minimally styled and provide you with a lovely area to use and store your essentials. It also helps in preventing damage to the bathroom furniture should the floor get wet.
However, you will need to consider the strength of the wall these units are being fixed to and of course consider how you will be concealing the hot and cold water feed pipes to the tap and the waste pipe of course. Probably best to consult your professional installer/plumber for advice.