About Edition 6
He made a declaration a few days ago:"edition 6 is better than the HE1000 v2 by miles, and you will hear this within 5 seconds, I promise."
I'm sorry, but I really have to laugh at this statement.
The reason I can is because I was just at CES, and I just listened to the Edition 6 and the HE1000 v2 on the same setup at the Venetian hotel suite they were demoing the headphones in. The setup was Hifiman's HM901S DAP hooked up to the EF1000.
I didn't do exact volume matching, but I did try do it by ear (not the most reliable way, unfortunately). I was swapping back and forth between the two headphones on the same setup for about 10 minutes. Listening was done in somewhat noisy conditions, though I found that by cranking the volume up it was enough to drown out most of the noise.
To get to the point, basically I could hear almost no difference in most aspects between the HE1000 v2 and the Edition 6. Perhaps with a longer listening session I could maybe hear some differences, but nothing in my listening session really jumped out at me. The tonality of the two headphones is extremely similar. At one point I thought the Edition 6 might have slightly better bass (as in more well-controlled) but AB'ing them I felt that I couldn't reliably tell a difference.
There are perhaps two things that differentiate these headphones. One, the HE1000 v2 has a taller soundstage, which I actually like better and IMO better immerses you into the music.
The second would be that the Edition 6 is extremely inefficient - much more so than the HE1000 v2. With the HE1000 v2 connected to the EF1000 via the 6.3mm single-ended output, I had the volume knob at around 9-10 o'clock. With the Edition 6 connected to the 4-pin XLR output of the EF1000, I had the volume knob at around 1 o'clock.
Oh, and one more thing: at this stage, the Edition 6 is noticeably heavier than the HE1000 v2, though the Hifiman rep I spoke to said that they're trying to get the weight down by the final release, as well as change the color of the wood veneer from its current lighter color to the darker color seen on the Shangri-La.
Most people probably wouldn't care about these impressions since it seems like nobody here at least would really consider these, but hopefully somebody will find these brief impressions interesting.