The waterpic 450 does a phenomenal job of flossing. I was at the DDS for my 6 mo cleaning yesterday and my hygienist commented that she sees a major improvement and after only one month of use. So I am very happy with the device and ease of use.
However I am disappointed that there is no charger light on it telling me when the battery is fading or when I am charging it when it is fully charged. Maybe there is another model I should have bought that has that.
Also it seems that I have to charge it more often than I expected to.
If not for those two complaints it is a great device and I would have rated it as a 5 for efficiency in cleaning. I look forward to using it. I did not look forward to flossing. And it is well worth the price.