Got mine this morning, and have been experimenting for awhile. Here are my super early impressions (take with a big ol' pile of salt).
The comfort is not bad. The ear pads are big enough to wrap around my ears entirely, and are deep enough that my ears don't touch the driver baffle. They do touch the inside of the pad slightly, but that's not a problem at all. The weight is what you would expect from a normal dynamic driver headphone, and much lighter than I expected considering it's a planar magnetic. Clamp is also pretty good. It's not too clampy, but it is clampy enough to prevent the headphones from falling off when looking up or down. The headband isn't as good, however. It's kind of like the Viso HP50 headband in that it's pretty flat/squared off at the top (where it should be round in order for the pad to maximize head contact and minimize hot spots). There is a hot spot at the top of my head, but because the mobius is so light, it's not much of a problem. It does make my head a bit itchy, but so far hasn't caused any major discomfort on the top of my head. To Audeze, check out the HD800 or the Meze 99 Classics when designing the Mobius 2, both are phenomenal examples of how to design a comfortable headband.
Hiss on my unit is extraordinarily minor. If no sound is playing, I can hear a really faint hiss on the left side. However, it's so minor that I won't be noticing it during normal use. This is on USB, I haven't tested bluetooth yet.
When you first put them on, all modes default to 100% volume, which is loud as **** and scared the crap out of me. Don't think I'll be having volume problems.
These little bastards are detail monsters. Really impressive detail retrieval (mostly in the bass and mids, the upper treble can kinda turn into a one note tizz, I think because the upper treble is elevated, more on that later).
As a downside of all that detail, it definitely comes off as a more clinical headphone than I would expect from Audeze. I wouldn't call these lush, and I'm not sure I would say these have the "Audeze sound" per se. They're not little LCD's, but that doesn't mean they aren't good. And I wouldn't call them clinical headphones in general, just more clinical than the LCD-series.
Are they a replacement for an LCD headphone? No. The 2C's I have (and the other LCD's I've owned and listened to) have a more lush and rich sound that these lack. And the LCD line is most definitely better than Mobius. But again, I wouldn't say that means Mobius doesn't sound great in its own right.
I played some FarCry 5 on these for awhile to test the surround sound. At first, it felt kind of strange, objects don't really have a 3D space like true binaural, but more of a general direction they're coming from. However, after using them for awhile, I got used to it and really enjoyed the experience. When using 3D and surround sound, small sonic details really jump out at you, and it's a pretty different experience. The rear sound is also pretty good, better than I've heard from other surround sound virtualizations. I think people are really going to enjoy these when gaming.
Now here's the killer, and the reason I'm not sure if I'll be keeping them or not. The upper treble is sharp, like headache-inducingly sharp sometimes. If I listen to electronic that isn't super well produced, it really comes out and gets uncomfortable, and that goes for games too. Glass breaking, the sounds of my own guns, and other brighter sounds get pretty uncomfortable after awhile. Cymbals are also too forward, and because of the upper treble lean, they end up just blending together in a tizzy mess. This is why I think it's important that we have some kind of cypher-like custom EQ that saves itself to the headphone. Even if it was just part of the windows app. I just want to be able to tone down that upper treble permanently. Small annoyances like this can mean the difference between loving a headphone and selling it, and an EQ system is a good solution to those problems.
Bass digs deep, but seems to be shy of neutral.
Overall tonal lean is bright of neutral (my neutral is the harman target response). It has less bass and more upper treble compared to neutral, no matter the setting, since it seems the settings just affect the midrange.
I'll be testing bluetooth next, both with my phone (iPhone so no LDAC) and with my Apple TV, which should test distance pretty well. Will report back.
EDIT: After listening to music on my phone through bluetooth, I noticed the headphones sounded somewhat bassier, warmer, and had less upper treble than on my computer. Something might be up with my computer, will investigate.
Edit 2: After more listening, they do seem too treble forward in all modes for me. I do still notice a slight treble elevation using the PC compared to Bluetooth, not sure why. Comparing high res pc to 3D off Bluetooth. Despite that, even in its least treble forward settings, it’s definitely too bright and causes fatigue/discomfort for me. EQing the treble down helps a whole lot.