I spent most of yesterday listening to the Aeon after receiving them the night before, and thought I'll send through some of my initial comments:
In terms of build and comfort, all I can say is that it's just perfect. I love the unique look and feel, it is super comfortable, and isolates shockingly well. When I first connected it I thought I wasn't getting any sound, only to realise that because the pads were resting against each other, no sound appeared to leak
Sound-wise: I did all my listening through a Corda Classic, fed by a Bifrost Multibit. The first thing that became apparent as I started listening was that these cans are detailed in the treble and mids. Really, really impressive amount of details. It emphasised some micro-details in recordings, such as the hum of a resting amplifier, the echo of a singer's voice in a recording studio, or talking in the background in a studio. These cans seem to bring to light more details than any other headphone I have, including my personal favourite modded HE-500, the Oppo cans, and definitely the HD-650. While I don't have it on hand to properly compare, the last time I heard so much micro-details was when I had a review unit of the HD-800S on loan. This was a big surprise.
The details seemed to mostly be in the mids and highs though, because in the first couple of hours the bass seem to be non-present - I was getting very little detail and quantity in the bass department. I tried the foam inserts, and while they increased the quantity a bit, the details were still not there, and in the bass the Aeon was no match to the other headphones I mentioned. However, this have noticeably changed after 2-3 hours of use, and all of a sudden bass details started becoming clear. I am still on the fence about the foam inserts as they only seem to slighly increase the bass body while possibly slightly veiling mids/highs details, however I have a feeling that the sound may still open up further after some more hours, so I will do another comparison with & without the foam inserts then.
Also, in the next couple of days I should be getting the Auralic Taurus MKii, and based on specs I expect its SE output to be a good match with the Aeon (low impedance, high current). In about a week I will do a more proper review and comparison with HE-500, Oppo PM-1 and PM-3. Until then, happy listenings! I know I am.