Like you need me to tell you, but the HD800 sounds stupendous on the KG Safetified Supra Killer Version.
What I love about the HD800 is you don't need to crank it up to ear splitting volume to get maximum resolution. But you are also free to crank it up and rock out, if the source material allows it. This is the opposite of my experience with the HD650, which always needed to be at "reference" volume level to let all the goodness come through.
one of my favorite things to test any hi fi component is listen to a soundboard recording of a show I was at. listening to a phish show from alpharetta this summer, and I can feel the venue. so awesome. the HD800 is the "rightest" sounding transducer I've heard this side of ESL-63s.
the dogs want me to quit paying attention to this new thing and pay more attention to them.
it is laughingly enormous though: