i have tried both but don't currently own or use either one!
my personal thoughts: i had an oral b one (the professional care 8000 i think) right before i got my braces. i didn't really like it because i thought it was too noisy and the spinning of the brush head seemed way too intense for me. perhaps i was just brushing too hard in combination with the quick and hard spins of the head, but i didn't enjoy it that much--though it did leave my teeth feeling clean. i then got my braces and stopped using it because i was afraid the bristles would all catch up in the brackets/wires from the spinning.
![SmilenRoll :-*](./images/smilies/toothy12.gif)
but i know people on the board have def used it with braces so it isn't really a problem. i moved out of college in the middle of all this and somehow lost the brush along the way.
i have also tried the sonicare (elite 7300) because my boyfriend owns one and has an additional brush head that he lets me use when i visit. i personally prefer the sonicare, because it seems to make less noise (and is more like a buzzing, which i guess is the sonic bristle action?) and feels less harsh on my teeth. and it leaves them feeling super clean!
so regardless of which you choose, both brushes seem to do what they advertise. but like everyone else has said, it's a personal choice! and i definitely agree with buying through ebay if you can--they are much cheaper that way! when i bought my oral b through e-bay it was about $30-$40 less than in stores (including target). good luck with whatever you end up doing!