they probably dont look all those reviews online about these, i got curious and most of them said they stopped working, or some part of the smart features becomes defective within a year.

anything above oral-b 1500 series, you are asking for it. 1500 and below you are just getting the standard rotating toothbrush with no smart gimmicks, and they last alot longer too. plus, oral-b makes thier money from the toothbrush heads, its every 3 months replacements, but the official replacements heads are expensive. if you are buying the IO series you will have to get those.