After a few days of owning them, I feel like the HE-400 might be end game for me. I got to listen to them properly amped for a day before the amp died, probably due to ecstasy overload. The sound was just luxurious, and the instrument separation and general intimacy was on a level I've never heard from a headphone before (granted, I've never been able to demo a really expensive headphone). Once the replacement amp gets here I will probably be content with these (plus the MDR-1R for portable use) for a very long time. I'm super excited.