Review (3/5): I love this toothbrush, but...
1. I don't understand these reviews that complain about getting water into the battery compartment and corroding the batteries. I've never had this problem. It would seem that one would have to be really careless for this to happen. Don't submerge it or pour water over it, and you should be fine.
2. Don't worry about battery life. Get some Eneloop rechargeables, and swap them out anywhere from a couple weeks to a couple months and you'll be fine.
3. This does such a good job, my dentist assumes I'm flossing like I'm supposed to be. I'm not. I do use a waterpic, but only a couple times a week these days. My dentist gave me an A+ on my last visit (part of this is because of the fluoride rinse that's been helping strengthen my teeth, but that's another review).
So now to the reason I only gave it three stars.
I had one of these that we bought years ago. I don't remember how long, but it's been probably 5 years. I'm not exactly sure, but it's been awhile. It's always worked great and still does. We finally got tired of sharing, and when we saw they were only $20 on Amazon we got another one.
This second one has had to be replaced under warranty twice in about a year and a half. It just stopped working, both times. No corrosion in the battery compartment or anything. The unit looks pristine, it just stopped working.
The first one lasted about 8 months. The second one only about 6 months.
So while this is a great product (functionally) and I would still likely buy it again if my current one died out of warranty (can't beat $20) I'm getting concerned about the quality. Here's hoping third time's a charm.