Well, that's only one very knowledgeable person's opinion. See also Blackmore's review in the high end forum. I can't say I'm over-fond of K70x and its variants. In general, I think the old firms did their best work ten or more years ago.
I can say that I loved my friend's Q701 and that it measures extremely well. It's incredibly similar to the HD800. People often make the inference that the Q701 is the K701, but there were changes made. The K701 had some nasty modal breakup around the 2kHz region (lower treble/upper mids). The Q701 doesn't have this issue, making it a lot more transparent.
I haven't heard the K812, but if the measurements are any indication I'd like to buy one and put Q701 drivers in it so I can have the gorgeous/comfy/gloriously constructed shell and the incredibly competent sound, that is unless AKG releases a K912 any time soon.
Edited by takato14 - 3/29/14 at 5:47pm