I just started listening to THIS (perhaps 15min of it on my drive to work this morning), and EY has already mentioned a little about traditional rationality vs. where he is now with respect to reading Feynman. I'm not sure if he'll talk more about this, but Luke's page does have as a bullet point of the things covered:

Eliezer’s journey from ‘traditional rationality’ to ‘technical rationality’

so perhaps he'll continue in detail about this. Off hand, all I can specifically remember is that at one point he encountered some who thought that multiple routes to solve a problem might lead to different, but correct, answers. Then he read Jaynes, who said that this was all wrong -- all mathematically valid routes to real solution should and will converge.

Also, there's a whole series of posts on EY's "Coming of Age" HERE, but maybe you knew that and still aren't satisfied.