Initial impressions of these was a bit ho hum, but in reflection that is where these headphones really shine. No matter what you throw at them they will retain an air of dignity and restraint, and they would never do anything so vulgar as to shout in ones ear.
The overall presentation is very neutral and refined, and not unlike my HD650's in their measured and polished manner. Treble or bass junkies these are not the headphones for you, however they will surprise you in their ability to reach the lowest of the lows, and the highest of the highs without ever sounding strained.
Overall these require a more refined pallet, and acoustic or vocal centric source material to really shine. But its the tone of the delivery that will get your attention, where the warmth and natural sound is just so beautiful.