Got them today. At work on my Fiio E7 they were better than my Usone 750's but nothing to scream about. Now at home with Apogee Duet DAC / LD MKIII Amp and wow. So nice. I'll be taking my Usone 900's to work and mothballing the 750's. I've been looking for a closed phone as comfortable and musical as my Grado PS1000's and these are it. Found them on Amazon for $389.
They actually isolate better than the Usones, and the pleather is not unduly hot. They are not sensitive to head position. The bass is incredible, probably due to the 50mm drivers. And very precise. (Usone 580's also have 50mm and have nicer bass than the 750/900's). The balance is nice, the fit & feel is very nice, and while the clarity doesn't beat the PS1000's, the bass does, and for pop/trance/electronica they are actually superior. It does an incredible job with dynamics, from thundering bass, to whisper quiet ambient sounds. No compression.
The PS1000's will magnify the heck out of any flaws in the recording, the Denon's are more revealing than the Usones, but still let you enjoy MP3's at a decent bit rate thru good amplification.
Usones do a great job of emulating open phones, the treble is light, detailed, airy, but very sensitive to the position on your head. I think Denon has one upped them in comfort and listenability.
Good closed phones are VERY hard to find. These are amazing.