Hi all you friendly people I just recently found this website and I thought I would ask if any one knows about the head replacements for the sonic toothbrushes that Pricedrop/Bid/Speedauction all sell. They seem very good value but not if replacement heads are hard to get! Do any of you have a sonic toothbrush? What do you think of it? I have an electric one but are the sonic ones really that much better?