Just wanted to share a video from youtube, starting from second 43:
https://youtu.be/d9fPqkIhcl4?t=43
The no-brainer feature for me for buying this device, is the fact of allowing to take notes besides an open document and immediately allow you to quickly zoom in an area, not necessarily using circles to highlight them, but instead using straight lines, like in the video. My main use case, so delightful, my super WOW for this device :-)