These brush heads work really well. Teeth feel fresh and smooth after brushing. In my opinion, they work better than a manual toothbrush; teeth feel extra clean and fresh. Personally, I get the itch from electric toothbrushes with rotating brushes, so I find the Philips sonic brushes that move back and forth a real godsend. It's also handy that the toothbrush indicates when the brush needs replacing, although that's obviously an unnecessary luxury.
The brush heads are a bit pricey, although they are cheaper than the more luxurious Philips Sonicare brush heads. For me, personally, despite the price, it's still worth it.