It's possible the demo is faked, and I'm skeptical. But I also don't think the speed is really the point of a device like this. Getting out a device, pressing keys or tapping on it, and putting it away again, those attentional costs of using some device... I know something like basic notetaking would feel really different to me if I was able to just do the thing in the demo at high accuracy instead. That's a big if, though - the accuracy would have to be high for it to really be useful, and the video is probably best-case clips.