I use the Sonicare for years (except for a small slip with a Sonic Complete) and must say that these are the most amazing essays I've ever used. I have a FlexCare and the difference to the normal essays you realize really. I feel that the toothbrush with the essays more strongly vibrates and the cleaning effect is even better than they already. Just be aware, because the toothpaste more stritzt as essays with other ;-)
just buy it - mainly because they priced barely differ from other Sonicare essays (at least on Amazon).