- "Virtual" time (fast-forward time) - Session isolation (even for same origin) - Full page screenshots out of the box
Slides for Chrome headless: https://docs.google.com/presentation/d/1gqK9F4lGAY3TZudAtdcx...
Shameless plug: I'm using Google Chrome to drive https://urlscan.io and will make the switch to the headless version once it's included in the Beta channel.