Right now it's one of those rare moments when I have two great cans at the same time: Arya Stealth and HE1000 Stealth. To be honest I'm struggling to hear if they actually differ at all. To me they sound pretty much the same. In any case, if someone is considering what to buy, I'd say you can buy the Arya Stealth and won't miss much.
Maybe I'm not picking the right material...I'm curious nonetheless so if someone can suggest particular songs and timestamps that would make the difference more clear, you're welcome.
I actually think that the difference between these Stealth cans is minuscule at best, I would take a wild guess and say that it's all the same: drivers are the same, technology is the same, the price difference comes from material costs and PROBABLY Hifiman tests the drivers and those that perform a bit better go to HE1000, those that perform a bit worse go to the Arya etc.