I used the original Sonicare over ten years ago, and have tried other battery-operated toothbrushes over the years, but this is the first toothbrush that I've used that gets my teeth "dentist office" clean. I use the stiffer bristle head, and find it not too stiff to hurt my gums like manual brushing with medium-stiffness brushes would do. This works like a charm --- just glide it along the gum line and it cleans your teeth and massages your gums. Batteries last a long time with this unit, certainly longer than I expected, and the brush heads last a long time, too. I use an external battery charger and rechargeable batteries to save some money and reduce the impact on the environment. The replacement head design is a snap-on rather than the old screw-on heads, which cuts down on cost and waste. I'll never go back to a manual toothbrush again!