I never met him, but I heard things from other students. At least when I was a student (and, who knows, maybe now as well) he taught a regular undergraduate class and ran a research lab with PhD students. Now that I'm a prof at a place full of administrators disconnected from on-the-ground reality, I deeply appreciate Chancellor Yang. I wasn't in his department, but I was studying at a place run by someone who was connected to how things work. If some Deputy Vice Associate Whatever wanted to implement some new policy, Chancellor Yang would have to think "Wait, what will it mean if I have to run my lab according to this rule? Teach my class with this in place?" It must have kept things grounded. It's probably why it was and is such an amazing university.