That his work is phenomenal is obvious, but his ability to share useful/repeatable techniques on DVD has always really impressed me. You can learn plenty just by listening carefully to the approach he describes on several design topics.
It’s really fun when he freestyles a construction before your eyes using bits and pieces of technology/animal shapes. Even if you aren’t ever going to attempt an approach on his level of visual mastery, there’s something for everyone.
What’s really fantastic is that he now has his own design school!
How cool is that?
I can’t really think of a better way to learn.