The Sennheiser HD-600 easily beats any Grado, IMHO; especially when driven with tubes. IF I COULD AFFORD THE STAX OMEGA 2 007, I'd buy it in a second. The only thing that troubles me with esl 'phones is that the thin plastic membrane isn't as acoustically transparent (to the back wave reflection from your ear) as the foam-cellulose diaphragm in the best dynamic headphones. Seems like it'd cause all sorts of echo reflections between it and your ear, however open to the outside it is behind the diaphragm/stators. JUST A CURIOUSITY, I have no evidence to support whether there is a significant effect or not...
