I've also had my Cybersonic for 3 years. I've never had a single problem with it.After 3 years, the built-in rechargeable battery is starting to lose its life, and I'm not sure how to replace it. But, it can still run for 5-10 minutes on one charge, so it's probably got at least another year of life in it. It's lasted longer than my cordless phone battery, so who can complain?I've never had a problem with the brush heads. In fact, they last much longer than the literature indicated they would. Hint: put them in the dishwasher at least once a week to disinfect & prolong the life (top shelf). Maybe the reviewers below ordered generic replacements?For me, this has been a terrific investment. I just keep ordering replacement brush heads from Amazon or eBay, and when the Cybersonic dies, I'll definately buy another one.