Oh, he's improved over the years. You should watch his very first presentations, during the Quake era. I think he's taken some speaking lessons to diminish his "uhms". But yeah, he's fearless of the public, which removes his mental blocks. I used to stutter in front of the public, but the one thing that solved it for me was a course, where we had to improvise in front of a camera. At the end, the coach replayed every video back to us. Every participant felt so much cringe that it ironically solved the issue.