The brushes are very soft, feel great in the mouth, and do a good job brushing. I prefer these brushes to the ones that came with the older model that had toothbrush and flosser as separate entities.
Brush Head appears to be quality. I have only had the product about a month so at this point the durability is unknown. Size is good and bristles are about medium hard. Water Jet stream is strong through the brush. I find that brushing first with toothpaste and then performing the water flossing after brushing is most efficient.