My HD800 finally arrived yesterday.
It's of course not burned in jet and since my HD650 sounded noticeably smoother with more bass after about 100 hours, I guess the HD800 will have a similar effect.
There is absolutely not doubt that it surpasses the HD650 in detail, sound stage and clarity.
The best compliment for the HD800 was made by my sister and her husband, who don't know much about headphones. Both thought that I'm nuts to spend so much on a headphone but after hearing a few song with it both suddenly completely understood why I bought it.
People say it's not the WOW phone like the Denons but that's just not true, they sound so huge it almost makes you dizzy when you close your eyes.
So far I'm very very happy with the HD800 and knowing I have maybe the best headphone in the world on my head is a sweet feeling too.