I don't want to burst anyone's bubble, but 9 DoF is marketing talk. In the videos that I've watched they can only do rotational movements, so really it's 3 DoF. If they manage to add positional changes as well, then it's 6 DoF, which would be nice because then you can actually peer at something, or look around an object. 9 DoF is only found in alternate universes.
They do simulate positional movement of the head when tilting, but that is simply achieved by putting the anchor point of the camera at the neck. So everything rotates around your neck (and not your eyeballs, the location of the camera), and as such you get the sense that when you touch your chest with your chin that your head moves forward somewhat. But it's not actual XYZ positional changes.