Well, I spent a few hours listening to music and gaming comparing it to my HD650.
Gaming
Personally I did not find 3D feature compelling, so I switched it off. Compared to my HD650 these have a lot more treble, and to be honest I simply get too tired playing games in these, the amount of treble in first person shooters makes my head hurt. Switching back to HD650 does make me feel like some of the clarity has been lost, but at least I can spend more than an hour playing.
Music
These are my first planars, and aside from hissing issue I do like what I hear. These are faster than HD650, they handle complex guitar and drums in Metallica Ride the Lightning noticeably better than HD650. To be honest, it almost feels like listening to a completely new album it sounded so good. Sub bass impact is also quite a bit more pronounced, for example Marilyn Manson rendition of Tainted Love has quite a bit more impact in the low end. I tried switching between different EQ modes, but to be honest I didn't hear much difference, I think I need to spend more time before I can make any judgement.
Movies
Amazing detail, I can hear all the sound effects I haven't heard before. So much more immersive than HD650.
Hiss
Hiss is definitely there and it is annoying, and contrary to the my earlier assessment, I can definitely hear it when playing certain music tracks/games/watch movies. I can hear it in games when there is a quiet moment, and similarly I hear it in suspense movies when there is a quiet scene, again, extremely annoying. Again, I thought all new shipments were supposed to be fixed. Can Audeze confirm?
Not only that, but when I switch to 2CH mode with 3D on Manual/Auto I also get weird static like noise that is sort reminiscent of in the old days when TV had no signal, and it's even louder than background hiss. Funnily enough if I hit play, then pause while using Foobar/ZoomPlayer, the static noise continues for exactly 20 seconds, and then stops. If I hit stop, there is no static noise. I have no idea What is happening, but there is no way this is normal. Either my pair is defective, or Audeze seriously messed up during design phase.
Can anyone confirm the hissing issues and weird static in 2CH mode and 3D Manual/Auto while playing audio/first 20 seconds after you hit pause?