The new Denon headphones are in line with the current design philosophy: slap a Made for iPhone/iPod/iPad label on a lavishly painted box, throw in an Apple-compatible cable and a half-@ssed case/pouch, done. Those headphones arguably prioritize looks and versatility over sound quality. So just make sure you know what you're looking for. And out of the high end audio companies that jumped this bandwagon Denon just so happened to put out the most respectable sound quality as well as build quality/comfort. I've tried 1R, UE9000, B&W P5, h/k NC, etc. and none came close to the D600, let alone D7100. Poor comfort, bad build quality, sub-par sound quality, those Apple-friendly headphones fail in one category or another. I've never had such issues with the Denons so it was money well spent so far for me.
I still regret selling my D600. I feel like the D600 hits the sweet spot between price and sound. The D7100 is better but not twice the price better.