FWIW: Five years after first posting on this thread, the incredible DX1000 remains my number one favorite. Paraphrasing Leonard Cohen, I tried to leave them. I really did. I worked hard on loving other phones more than the JVC. And I did find other models which proved, in one way or another, irresistible to me: the Sennheiser HD800 (fantastic microdynamics, most comfortable of all, sweet, extended highs, very three-dimensional) and the flawed-but-charming Grado GS1000i (midrange candy, airiness, light on the head, plausible headstage), primarily. But I have also found much to like – love, actually – in the Denon D7000 (overall, best bass I’ve known, highly neutral, excellent soundstage depth), the AKG Q701 (widest soundstage, comfortable, good 3D) and the Senn HD650 (excellent soundstaging/three-dimensionality, good bass). I’d be happy with any of the above as my single pair of headphones. Each of them has a number of minor flaws. But each of them delivers at least better-than-entry-level-high-end SQ. None of them can fairly be called “mid-fi-ish”, IMHE. (Give them top-notch amp & source! If you hate any of them, you’re putting the blame in the wrong place!) And yet, after all these years, not even the most obviously impressive of them, the one that most obviously conveys a sense of “audio truth”, the HD800, delivers as much all-things-considered sonic goodness as the DX1000.
Since buying the DX1000 five years ago, I upgraded the amplification four times and the source three times. I’m now listening to my best amp, the phenomenal Audio-gd Master-5 (simply jaw-dropping!), and my best source, the Audio-gd NFB-10SE balanced DAC. (And there’s a new, presumably better Audio-gd DAC coming my way, the DAC19.) I have also paid handsomely for power conditioning. Through all these upgrades, one thing hasn’t changed: the DX1000 never fails to put a smile on my face. It’s never boring; it’s always surprising, but very judiciously, very cautiously, very cleverly so. Five years later, I’d repeat every word of praise I ever said about the JVC in numerous posts. Yes, these phones do depart from perfect neutrality. And yet, yes, they do so in such a seductive way that even this neutrality freak can’t help but prefer their slightly sugarcoated version of the material to anything that we might want to call “audio truth”. (But, no, they can’t properly be called “euphonic”. It’s more complicated than that.) They win me over every time. I know I’m being manipulated; I know they’re meddling with that, and then with that too; I know that they’re putting more there there than is really there. And yet…somehow, for the most part, that’s how it all should be! 
I also agree that amplification is to blame.
