The design, ease of use, technology, and ability to whiten teeth without causing increased sensitivity are all things I have loved about using SNOW. It is far and away the best product I've ever used when it comes to those criteria. I haven't seen the dramatic whitening I was hoping for quite yet (2 months in of regular 30 min sessions), but it's definitely helped and I don't plan on stopping my use anytime soon. Overall, I've had a good experience with using SNOW.