The original spare brush for Sonicare are unreasonably expensive and I tried it with these compatible. At first glance, they look like the original and are also well on the device. After first trying out, I realized: The brush is harder and more unpleasant scratches on the gums. After that, I looked at it once through a magnifying glass. The bristle ends look like badly sawed and partly frayed. The material is also different, brilliant. The original, however, has slightly rounded bristles and makes no problems. For the life I can not comment because I'll dispose of these brushes - can give back something you do not.
A cheaper alternative to the Sonicare toothbrush people would Sanitas-sonic toothbrush that has my sister bought almost simultaneously. She has the same number of revolutions, and soft, rounded bristles and there are 7 brushes equal to it!
This rounded bristles are found incidentally even at a very cheap manual toothbrush from Aldi. Therefore, it is incomprehensible that a sonic toothbrush as an inferior stuff is produced.