Technically, it's an excellent talk about systems engineering. That is, looking broadly at systems, how you can significantly simplify and reduce the problem if you're willing to forgo interfaces. With that broad theme in mind, the actual talk ends up being a whirlwind tour through a lot of the VR headset and video/image technologies John was working on at the time. Excellent technical talk as always.
Learn third person dynamic game camera design strategies from one of the best. What's not to love! This is one of those talks where you can feel every single mistake as something they personally made and had to go back and fix. Listening I felt almost like I was right there with them when they realized it wouldn't work. Great talk format. I also love that the very first mistake they talk about is even choosing to do a dynamic third person camera. Basically, here be dragons.