The toothbrush head is a good shape and the battery lasts for a very long time - the main reasons I bought this toothbrush in the first place. But I have found a very annoying flaw in the on/off button. Because it is inset into the stem of the brush, the space around it easily gets clogged up with what I think is a combination of watery toothpaste and limescale. Then the button won't work, and you find yourself unable to turn it off at the end of brushing. This means frequently digging out the gunk, which I have not come across with other electric toothbrushes.