Dunno but I find D600 quite intriguing at that price and quite interested in hearing more about that one. It's gonna be hard to top or let alone match their old series in terms of sound quality though... rarely companies compete whit themselves which is how I see Denon doing in this case lol.
I just can't see the logic behind this move to discontinue old Dx000 series and introduce THIS? Any1 ever saw/heard any logical explanations as I don't see which sane company would do something like this as the Dxxx series was highly popular.
I would say offering both would have been the best step, but my guess was it may not have been economically feasible (since it is such a small market).
I'm also willing to bet that these new headphones give Denon a larger profit margin.