All right, here's my take on the equipment:
1) The HD800 admittedly is very, very good. It sounds more "electrostatic" than any dynamic I've ever heard before (in a good way. I'm suggesting the details are way better than any dynamic I've ever heard before), and the bass it produces is really quite impressive. Certainly, this headphone is much better than the HD650...whether it's $1400 good is certainly up in the air, I have to say. Like someone mentioned to me before they handed them over to me, "these don't sound nearly as different from the HD600's as I imagined they would." I can't make a full judgement on the 800's because the meet was noisy and they're really open (think Grado open), but I'll say they're a little brighter than I would prefer, and in my opinion, they're more like $1000 good, not $1400. Also, these headphones sounded way better on vpivinylspinner's rig than anyone else's, so don't go thinking you can plug these in to anything. My personal guess would be that these will sound best with a high-end Headroom setup since they specialize in Sennheisers.
2) HiFiMAN HM-801: What's wrong with this stupid thing? It's a freaking MP3 player... you shouldn't be able to just plug HD580's into them and hear amazing sound, yet you certainly do. I listened to this thing for more than an hour and made a hardcore comparison to my iAudio X5L, which I'll post in the portables forum. My overall impression is that it stomps my iAudio flat, and my iAudio was already basically the best thing around until this guy came along. Anyone interested in a serious MP3 player (that also acts as a DAC with USB!!) should check this guy out. The DAC part alone is really, really nice.
3) HiFiMAN EF2: Fang's latest amp is a different design from the EF1 and it's not an upgrade, rather, it's a sidestep to a more affordable option, plus it adds one ridiculously sweet feature... a built in DAC with USB. It uses two smaller tubes (6J1) as opposed to one dual-triode tube (12AU7). I was really quite, quite impressed with this amp. I normally run an EMU 0404 USB to Head-Direct EF1 setup, so the total for that rig is $500. This little guy, at $189, is at least 80% of my setup in terms of sound quality. The EF1 definitely has more detailed, open highs, and is more precise, but the EF2 clearly has more bass, which makes it more fun to listen to at times. Overall, I was basically floored by this amp. I'm going to have a hard time recommending my setup now because this is just so, so close, and it's 40% of the price. Did I mention that it has USB??? What a great little device, period.
In regards to the last two, Fang had me listen to the HM-801 DAC into the EF2, then the EF2's DAC by itself. There was clearly a difference, but I couldn't tell which was better.
4) Ethan (Yikes) has the most ridiculous electrostatic setup I've ever heard. I've never been much of an electrostatic person because they lack the raw, visceral feeling you get from dynamics, especially in the bass department. He had a Woo Audio GES with a HeAudio Jade and a Music Hall 25.2 DAC with some random CDP transport. Anyway, this was the best electrostatic setup I've ever heard, period. The bass was just utterly, utterly ridiculous (deep + copious amounts), and the highs were ultra-detailed like you'd expect, but so, so smooooooth. Ugh, this was the electrostatic setup, at least for me (I've never heard anything like it). Then again, it probably topped $5k total. Still, why did it sound so good? It was electrostatic. I was baffled. Still am.
5) Grado HF-2's. Good news for HF-1 lovers! These tell the same story as the HF-1's, but much better! I always preferred the HF-1's to the other prestige headphones, especially once you "fix" them by putting flats on them instead of bowls, but the problem with flats is that they really arrest the highs and the soundstage. The HF-2's bring up the bass nearly to the level of the HF-1's with flats, but have really, really nice open highs with great detail and a soundstage that improve on the HF-1's a lot. Overall, I'm glad I bought these and am looking forward to doing a full comparison against the 1's, although I was a little startled by just how similar they sound! Cosmetically, I didn't get a good look at these (or any headphone for that matter... as soon as I distinguish right from left, they're on my head), but what I saw, I liked. The lettering was a little odd-looking, but the aluminum enclosure is really nicely put together. Cosmetically, they really are a large upgrade from the HF-1's, even if the sound isn't necessarily $300 better.
6) Ari's little custom tube amp really blew me away. It sounded better with my HF-1's than the Melos. I had to ask him whether it was all right to like the custom one better than the Melos and he said it was perfectly fine, so I'm glad that I'm not nuts. The Melos-HP1000 combo is still completely unbeatable, in my opinion, and was the best rig at the meet.
7) Fang had a new prototype headphone that'll likely go for $1000 that is of "orthodynamic" design, that is, it's a planar driver between two magnets. It was really interesting, and ultra-detailed, but needed more bass (others agreed). He affirmed this and said that the production model would have a lot more because that was the main problem.
8) Tube testers are awesome. I need to get one.
9) DT880's still blow me away with pipe organ music, subsequently disappoint me with everything else. What a confusing headphone.
That's all for now. Thanks everyone for bringing all of their stuff, and thanks again to Larry for getting us the hotel! These meets are always eye-opening and this was even moreso than others. I could go on and on, but otherwise nobody will read this!