I know it's a bit off-topic, but curiosity got the better of me that I decided to order the legendary - and bizarre-looking - Jecklin Float QA and compete it directly against my HD800. It sounds like an unfair comparison given Float's much higher price tag, but the HD800 will be driven to its best with my maxed-out - P+G pot, SAA umbilical cord, NOS Mullard ECC35, upgraded fuse) ZDSE which cost me $3.5K. The Float and its transformer box, on the other hand, will be connected to the Pathos Classic One MKIII integrated amp ($3-4K). I don't know how well the Float QA scales with higher-end speaker amps, but according to QUAD, the Classic One should have enough power to drive the Float to its fullest volume.
As of now, the HD800 has been the reference headphone for me, winning me over other headphones I've tried including LCD-3, TH900, HE-6 and even SR-009; I personally didn't like the SR-009 that much, at least on the setups I've auditioned it with (WES, BHSE). The HD800 images like no other, throws a massively wide, spacious and airy soundstage around my head, and is perhaps the most detailed headphone I've listened to. The only problem is that it is very amp picky, which is why it took me so long to appreciate its true value. The only headphones I have yet to try that could compete (or possibly destroy) the HD800 are the HP-2, SR-Ω, R10, Abyss, H2+ and Float QA. The first three are discontinued and very hard to find (not to mention expensive), the Abyss is extremely expensive, the H2+ is supposedly very hard to properly tune its sound with the right amp, so the Float QA it was for me. I've read several users' feedback that the Float QA was better than SR-009, so I'm really looking forward to it.
If not even the Float QA has what it takes to dethrone the HD800, the Abyss will come next... but it will be a long time after.