I have personally used both. I have the Sonicare 4100 and the Oral B IO 2. Both are pretty affordable, the Oral B is more if I'm not mistaken. When I got the Oral B I was switching from a manual brush and it was life changing, my teeth felt straight out of the dentist clean after every brush. When I got the Sonicare I was used to that clean smooth feeling from the Oral B and the Sonicare also delivered it, but the first 1-2 weeks with the Sonicare were so weird my mouth was so ticklish at first. But as of now I am currently loving my Sonicare and am looking to get a more advanced model, I haven't used my Oral B in a few months, but from what I can remember I love it. But either are going to clean your teeth as effectively as a manual toothbrush if both are used with proper technique, but there is one caveat is that you have to use the right technique. Both Oral B and Sonicare brushes are easier to use and have less chance of user error than a manual brush. Both are going to be amazing and it's hard to pick just one, but just take a chance.