I'm sure it sounds good, but I would never consider paying anywhere close to $10k for a DAC. $40k is just hilarious. But hey, if it makes someone happy then more power to them.
If you put it that way, most folks who listen to crappy iBuds would find our hobby of investing $1-2K on headphones and amps hilarious as well. But hey, I'm not gonna judge unless I actually get to try them out with my own ears. I hope people here who find spending $40K on a DAC hilarious or ridiculous are saying that AFTER they've actually heard them too. If I were rolling in cash like David Solomon, so much cash that I could afford a Sennheiser Orpheus, two pairs of R10's, SR-009, SR-Omega, and another 50-ish headphones that cost around $1K or more, along with several amps costing $5K and upwards, AND still had like $50K lying around, then why not a $40K DAC?
Although I don't agree with his ranking of headphones entirely (okay I'll admit it, placing the TH900 below the HD600 is preposterous IMO), what I respect more than just his collection of headphones and gears is his dedication. And dedication is the main driving force behind these expensive hobbies.