Yep, he500 with the right set-up is pretty epic to listen to. One of my favourite songs is 'One of these nights' by The Eagles. I decided to try out the hd800 plugged into a v200 and listen to this song and it sounded terrible! The hd800s were doing what they are suppose to do which is showing the quality of the recording with a microscope. But on the he500, it sounded spectacular. And that's what good about these headphones, you don't have to sacrifice listening to crappy recordings with them.
The HD-800 never appealed to me. No doubt they're excellent at what they do, but I see no point in spending a small fortune on headphones which are so accurate and so revealing that they don't actually allow you to enjoy music. Then there's the matter of how picky they are with regards to ancillary equipment and their reputedly narrow (extremely narrow) genre bandwidth.
If I only listened to well recorded classical music and had the time, money and patience to assemble the right setup for them I may have felt differently about the HD-800.