This video has a lot of interesting stuff. First of all, the near actual (you can see from the mirrors this is still slightly above the drivers view) vision, or lack thereof from an F1 car. Secondly: the insane degradation of the tires over the few laps Di Grassi drives. And last but not least: the delta times on his steering wheel. Being able to exactly see how much a few meters past the braking point or a few centimeters away from the apex affects his times.

Here is another one, with a slightly below view.