More impressions of the Arya- I bought them two weeks ago and have been listening for a few hours a night. In a nutshell, I think they are amazing. Best hifi purchase I've made (providing they last me years).
First thing to say is that I listened to a lot of the higher-end headphones before buying these: Kennerton Thror, Audeze (all of the them including the LCD-3 and 4), Focal Clear and Elegia, Sennheiser HD800s, HD800, HD820, ZMF Auteur and Verite, Mr Speakers Ether 2, Abyss 1266 Phi CC, Diana Phi etc, Hifiman Arya, HE1000v2, HE1000SE, Susvara. Some I heard at CanJam singapore, others at local hifi shops. There were phones that were better than the Arya- the Abyss maybe and more expensive Hifiman, but not by much. The Thror was a similar level, but didn't have as much sub-bass slam to my ears.
I listen to a range of stuff, from acoustic to folk, to rock, to metal, to progressive house, drum and bass, rap. So I wanted something that sounds good with anything. To me the Arya is that. That said I do think the HE1000SE is a slight upgrade. More soundstage depth, slightly more detailed, slight improvements across everything. The Susvara was also amazing, very refined, but certainly not worth the extra cash and maybe lacking a little excitement. The Arya does so much that other higher-end headphones do, but at a fraction of the cost. Amazing, sweet-sounding vocals, stellar levels of detail and separation, great soundstage height and width and excellent transient attack. They just sound right.
I have the Hidition NT6-Pro which are known as being very highly detailed (Average Joe puts them towards the top of his list for detail and technical ability), but I hear things on the Arya that I have never heard on them. They sound natural, dynamic, fully extended at both ends, but without sibilance or bass bloat. They are not for bass heads, but the bass is incredibly textured and reaches low. It is enough for me. Bass was a major draw back of a lot of the other headphones- they just didn't have the sub-bass/low slam for dance tracks. The Focal Clear springs to mind here. They sounded great but a little lean.
The Arya sound so open and natural they are addictive. I've just been getting lost in the music with them, hours pass and I forget what I am doing- not great for productivity! My mind doesn't search for something they aren't doing as it has with other audio products in the past, like "ooh, I just want a bit more bass texture, or more holographic vocals, or a bit more clarity". Everyone who has tried these (people not into hifi) have been amazed by them. They are a legit piece of high-end audio IMO.