A:AnswerThe display is OLED monochromatic - the 9 is full color (unnecessary IMO). There are more brushing modes in the 8 and 9, yet given the 7 is more feature rich than a top of line Sonicare, it’s all one needs
A:AnswerThat’s just how the toothbrush is! It’s already off, it’s not going to Shut down 100% it will always be in rest mode when not in use. So if u move it or pick it up the display might come on. That’s how it is from the factory. It doesn’t even waste significant battery life in rest mode! Mine when not in use and not plugged to the charger and just laying on the counter collecting dust it lasts 3-5 days maybe more.. soooo yea u can’t really conserve the battery any more from the factory settings because it’s already at optimal performance!