I was there, and have been dying to leave my full impressions, but like SoundFreaq I've been utterly slammed with work since I got back to Dallas. Everything there was new to me except Liquid Fire, HD800, HE-500 (mine) and the EF5 & E17 (also mine).
A note on the SR-009- Nothing could have truly prepared me for this experience. As Morbid will surely tell you, I'm an avowed basshead. I'm from the 'neutrality is for sissies' camp.

I've never owned a pair of headphones where I wouldn't have been happier with a touch more bass. A touch cleaner, a touch richer. That's not to say I'd be terribly happy with recessed mids or lack of sparkle, soundstage, imaging, etc. In fact I seemed to gladly suffer through it for 2 years with my previous Thunderpants. That's one of the main reasons I am presently quite in love my HE-500s. They allow me to EQ my bass where I like it, and not have that bleed into the rest of the spectrum and enjoy a very well-rounded sound signature that works with all genres.
But I digress. When I heard the astounding detail present in bass through those SR-009s - the seemingly endless layers of texture, all those little subtleties in the bass I had never before heard (even lacking the typical level of bass quantity I often seek) - it was nothing short of a revelation to me. I realized in that instant that I'd gladly trade
any quantity for
that kind of quality. I've spent plenty of time listening to headphones renowned for their bass like LCD-2, TH900 now, my old TP1s, but never heard a fraction of the kind of bass I heard through the SR-009s. And that's not even going into how I felt about everything else in the headphones' presentation of sound.
A note on the HE-6- I, too found these excessively bright, fatiguing and frankly somewhat un-listenable on the LG (Granted, Squarepusher and perhaps not the ideal test track) with the tubes it had in it at the time (Shanguang Treasures I think). But I don't think this is the fault of the HE-6 at all. (Or the LG/tubes for that matter) My experience and Morbid's reflected exactly what others report when listening to HE-6 when underpowered. That said, I will reserve final judgement and make no determinations on these phones from the initial listen, and seek to hear them on an amp that pushes at least 8+ watts into each channel. A speaker amp ideally. Even better, MY speaker amp.
A note on the HE-500- These sounded downright stunning on the Liquid Glass, with any type of tube. That experience instantly made me start thinking about an upgrade, which will consume my headfi hobby for the foreseeable future. A truly lovely match.
More later. I have lots of thoughts on the TH900, PerfectWave, HD800, etc. but those will have to wait. Huge thanks to Morbid for an awesome weekend and SoundFreaq for coming and sharing your treasures with us; it was a real pleasure to meet you and look forward to seeing you both again at Austin meet or before.
Best,
Dave