First and foremost, thanks to all of the members and vendors who shared their gear with me today! You have my gratitude
I didn't have a chance to listen to everything on my wish list, but there's always tomorrow. So here were my strongest impressions with some select gear:
Sennheiser HD 800
Speed: I'd say it's on par with the Sony SA5000 in the speed department. There was no more, or less, detail to the rhythm guitar portion of the "Mechanix" solo, compared to the SA5000. This could be due to the fact that they suppress very little outside noise, which there was quite a bit of. Given that the SA5000s are quite fast already, I think it will be enough for most people.
Bass: There was more, and better textured, bass when compared again to the SA5000. Quite a bit more "thump" when it was called for. Most of the pairs I tried were single ended, but Ray Samuels did have a balanced pair hooked up to an Apache amp of his. There was a single ended pair right next to it, hooked up to a Raptor. Balanced mode did certainly increase the quantity of bass, but beyond that, I couldn't directly compare how sound quality was affected. I'm listening to this one again tomorrow, for sure. As an aside: I found Mr. Samuels to be a very friendly guy.
Everything Else: The soundstage is very big on these headphones, as is the earcup itself. If you prefer your metal more in-your-face, you might not appreciate the presentation of the HD 800. I'll investigate this some more as well. You can spend a bit of time moving them around on your head to find the right balance of soundstage and bass response. Moving your ears towards the front of the cans made more of a wall of sound, further back seemed to make a bit more bass.
Ok, the Grado PS1000 next. I heard these at Moon Audio's table.
Speed: A smidge slower than the HD 800, in my opinion, but still quite fast. This could be because the
bass was in greater quantity. The PS1000's are significantly warmer than the HD 800, and it sounds quite pleasant. I didn't think they have a huge soundstage, however. They were nice, a little heavy, and quite a contrast to the HD 800, actually. These were hooked up to a Cary Xciter amp, which produces an incredible amount of power--and heat. It sounded great though.
Stax Omega 2 MK1 / MK2: I actually liked the MK2 set up with it's matching amp. I also tried the MK1 and MK2 with the Blue Hawaii, and the MK2 with Woo Audio's electrostat prototype amp. These had the most
speed out of anything I tried, save perhaps the Jade electrostats. The "Mechanix" solo was portrayed the clearest I've ever heard it, but it wasn't a huge difference from the best dynamics. There was more
bass slam than I expected as well. Certainly more than the SA5000s, probably on par with the single-ended HD 800. I have to give them more of a listen to really form more of an opinion on them, but as catscratch said, they are finicky. I happened to get a really good fit while wearing them at Whiplash Audio's table, and I was about ready to proclaim a king of thrash metal headphones. Just a few problems with the sound bugged me (like snare drums sounding funky), so I'll be back with more on these later, for sure.
Ultrasones: I was unfortunately disappointed with most of these. Heard the HFI-780s, Edition 8 several times, and Edition 9s, though the Edition 9's were balanced.
HFI-780: not bad, but didn't wow me. I'll try them again.
Edition 8: don't bother.
Edition 9: These were also at Whiplash Audio, hooked up to a Little Dot MK VI. Sounded very high end, with good bass and natural sound.
JVC DX1000: These had a weird hollow coloration that I didn't like at all. Comfy, though. Like putting two giant marshmallows on your head.
That's all I can remember for now. Going earlier tomorrow to reaffirm some things I'm holding back.