Just sold mine. I've been agonizing over which to keep between the HE-6 and HD800 for a few days now, and the HE-6's combination of grain-free sound + the way it can handle any genre trumped the slight technical superiority of the HD800. Also, like MT said here, a slightly smaller stage just sounds right for some genres.
The HD800 simply did better though with perfect recordings. My interest in building a speaker rig is growing, so the HE-6 makes more sense as I invest in better power amps.
We ought to meet up/set up a meet sometime and try out our different setups