That's really interesting to read as I have the HD800's but have no personal comparisons as they were gifted to me.
I guess I really like my 800's but it's intriguing to wonder if the grass is greener I guess.
Glad to read these K812's are for you though
Side note: what's with all these headphones named by numbers (K812, HD800)? So dull IMO, I'm sure they could be a little more inventive but seems as if the naming process is almost an afterthought.