sonicare is the "OG brand" for sonic, its quite pricey, i went with offbrand one, it does the same with the fraction of the cost, plust it comes with 6-10 replacement heads. sonicare and oral-b only comes with 1 and you have to buy thier official or offbrand ones(which has questionable durability for the cheapest heads).

with oral-b, because i couldnt find a reliable off brand one i bought replacement heads for the official german rotating oral-b(its larger and it fits enough that it still works like the american ones, which was quite cheaper.