Compared to the old "design" of the heads I find the new managed the slightly raised side bristles clean felt intense / better. Otherwise remains to be said, the colors have changed and at the back of the head is only a small opening. (Whether this is less of injury reasons, I can not say, but I guess less air passage to dry, if necessary, as a hygiene problem a).
I myself sink and "shake" the heads of after use and put them to dry out openly (not attached to the handpiece or in an enclosed space, I have often seen)
