glass shelf and medicine cabinet height
I don't know if this helps, but the height of our bathroom vanity tops are 30" and 32". I'm 6', so wouldn't mind them being a bit higher, but my wife is 5', and they work well for her, so I doubt that I would change the height if/when I ever replace them. On the top end, assuming an 8' ceiling, I think that the top of the cabinet being at 78" in a smaller room like a bathroom may "shrink" the room a bit. With those two things in mind, I would probably frop the vanity a bit.