These are pretty decent. They are about 80% of the force of a Philips sonicare, but I actually prefer this over the Philips sonicare. It’s more durable for sure. I use the Philips sonicare sparingly and have had 2 toothbrushes start to crap out after a couple years. The AquaSonic have help up at least 3 years and at their price if it went out tomorrow- I’d be fine with it. These AquaSonic feel pretty premium also, they have some weight to them- not real light like some of the cheap ultrasonics.
Agreed. Also, the battery life is crazy. Seems like I charge mine like, every 4 months or so. Maybe I’m not brushing enough 
What’s the difference between this Black series and the Vibe series? And can you interchange the chargers and refill brush heads between them?
Poked around on their site. Only difference I could find was one is black and the other comes in 3 colors.
The page for the Black Series brush heads says it works on Vibe.