Firmer Than Other Heads [SEP] Compared to my regular replacement heads, these heads feel much firmer and more stimulating to the gum.  They also snap more firmly to my brush than do my regular heads and run more quietly.<br /><br />If I had to choose between the two, I'd choose my regular head first.  Because, however, I've already bought these and they may have some beneficial effects the regular heads lack, I've chosen to alternate the heads.  I use one head to clean my teeth with baking soda, then floss, then use the other head to brush with toothpaste.<br /><br />I've now been using this head for two months.  It only took a couple of days to get used to the stiffness and I wouldn't even notice it if I wasn't alternating the heads.  I see no evidence, however, that it cleans any better.