That's kind of cool. I'm in Australia so can't sign up. Concerns I'd have before signing up:

1 How good are the toothbrush heads compared to the better ones you get in the shop? I'd be concerned about downgrading.

2 I don't know which frequency option is best. What frequency do dentists recommend? Could you guide people here?

3 Does this work out cheaper than buying them in the store? Is there a saving here, or is it just about convenience?