Review (5/5): Maybe its cheaper, but it still does the job better
I bought one entirely because it was significantly less expensive than a Sonicare. I have had it three years and have yet to be able to run the battery down, which I find remarkable ... leaving it off the charger for a week results in very little if any loss of power.
I completely disagree with the reviewers who say that it doesn't perform better than the non-sonic brushes.
The first time I went to my dentist after having used it for six months, he sat back in his chair and asked me what I was doing differently. I told him nothing but changing to a sonic toothbrush ... when he asked me what brand it was, I told him and he said "Well, don't change a thing, because this is the first time you've had zero placque."
Its not supposed to be a substitute for flossing. Flossing once a week (which is considerably less than what the dentist wants) and using this brush have improved my dental health measurably enough that my dentist remarked on it, and I doubt you can do better than that for the money.