I've been using the brush heads for a few weeks now to test them. The small shape of the brush head allows me to reach the back teeth easily, where other brands often make it difficult to reach the back of my molars, but this one doesn't have any problems. I'm currently pregnant, and this toothbrush (the head) makes brushing much better than before I started using the Sonicare. The shape of the bristles is supposed to whiten teeth or remove stains, but I can't really say for sure after such a short period. At first, I had to get used to the vibrations; when you brush your teeth, it's not an annoying or loud sound, but as soon as the plastic, rather than the brush, touches your teeth, it takes some getting used to. So far, I'm very satisfied, and I hope to see a difference in the whitening effect in the future.