I thought it was curious when he was here that he would never list the components in his system. Most people who are into audio do not hesitate to list their reference components. I had the distinct impression at one point that they were low-fi.
Suggesting that Ethan is not into audio is sort of missing what he is about.
I purchased his 600+ page book, "The Audio Expert Everything you Need to Know About Audio".
It is quite detailed with lots of practical experience and sound explanations to back up why things work. With it he included a DVD with useful audio tracks for testing as well as his cello video. Ethan is a musician. He plays multiple instruments and he is also a bit of a mastering engineer.
His home stereo system is definitely not exotic. He does have elaborate room treatments which only makes sense since he sells room treatments.