Outside of the JHA people, I don't think anyone has heard the the JH3A/16 extensively, let alone compared it to the HD800s. The 3A/16 debuted at CanJam, and people were lined up from the start. I'm extremely doubtful that anyone had the opportunity to listen to more than a song or two at most before giving someone else a chance. I was able to listen for about five minutes on Saturday and about the same on Sunday. I'm certainly not willing to answer questions about how big the soundstage was/is or how the treble's "airiness" compared to anything specifically, especially talking about it a week after the fact. I'd be guessing and making it up. I will tell you that I'd been listening to the JH13/slim/ipod about a half hour prior to getting in line, and I was struck by the precise imaging and a sense of layers/textures with the JH3A/16 combo that simply seemed more vibrant, more lifelike than with my JH13 rig. How much more? I dunno. How does it compare to my home rigs, all the other rigs I've owned or heard extensively over the years, or even the rigs I listened to there at the meet afterwards? I have no freaking idea outside of basic sound signature differences and preferences. I don't know about anyone else, but my audio memory isn't that good, and I sure wasn't doing an in-depth comparative analysis in my two five-minute sessions because I was busy just smiling a lot.
Meets are wonderful, mostly for hanging out with great people, but also for a chance to get a taste of gear we're not familiar with that well. A taste. Large meets, where a lot of vendors are present, offer that double-sided coin thing where you can hear a lot of gear, but for the most part, you're in an unnatural, crowded, noisy setting, and even if you're familiar with certain headphones, you're usually not familiar with the amp or source or music, etc. How the heck can you say anything true about any one thing other than provide very initial, yet real nontheless, impressions? Some of the best headphones aren't great meet headphones. Some of the better amps get dismissed because they "disappear," etc. and on. Sometimes, if you're lucky, you have more time with meet gear and can do real comparisons or in-depth listening (I was lucky enough to have an hour or so with the ttvj/millet pinnacle amp after hours), but that's usually at smaller meets, and even that experience gets muddled when you've just spent five or more hours listening to multiple rigs while partying with your friends.
Here's my take on things:
1) The JH3A/16 was impressive enough on my initial taste for me to throw down my credit card after one song. When I receive it in September, I'll spend a few weeks/months with it, and maybe then have something to say that's not just a tangle of new toy love mixed with accurate, thought-out reflections. Others might be faster and better at getting decent impressions/reviews out. I'm just not that good, and neither are most people writing on this forum, including some who like to write a lot. The great thing, though, about a forum is that it's the collective experience, over time, that usually brings us a fairly good idea of a piece of gear.
2) It will not be replacing my main home rig, an APL modded Phillips SACD1000>Headamp BHSE> Stax SR-007BL. My rig kicks ass.
3) It will not be replacing my speaker rig. It kicks bigger ass.
3) It will not be replacing my ipod/pico slim/twag micro lod/JH13 rig. The qualities of the JH3A/16 do not diminish the qualities of the JH13 one bit. I bought the JH13s at CanJam last year and they still make me happy every time I put them in my ears. It's the perfect portable rig for me...oh....and btw, the only reason I'm going for the 16s with the 3A is that you can control the bass. The 13s have the perfect amount/quality of bass, imo, when amped well. I love my JH13s.
That's about all I know at this point. I hope to know more in the Fall, and even though some of you want specific answers to specific sound-impression questions, I advise that you wait to get those answers and not be sucking on every little tidbit and then blowing it up. This thread is already turning into a monster of stupid impressions, and not by the people who have heard the J3A/16, but by the people who haven't. I really wish a couple of you would knock it off. It does everyone a disservice.
On the other hand, if you're looking to learn if it's hype or real, one indicator you might want to pay attention to is who, after hearing the JH3A/16, bought it instantly: immtbiker, bozebuttons, vpi, jp11801, Edwood, etc. These guys, with years of experience with pretty much every rig out there, don't buy hype.