After putting a few hundred hours more on these things, I'm absolutely astounded by them. They just keep getting better and better as I put more time on them. Great throughout the frequency range. They're one of the few headphones I've heard that can render convincingly distant bass in the soundstage. Treble in active mode is rather 'hot' though. It needs quite a warm amp to tame it a little.
Superb for Dolby Headphone use with the SU-DH1 (which drives them very well). Add Auzentech Prelude to the list of sources that doesn't produce enough juice in passive mode though.
Having had them both a while, I now rate them higher than the Goldring DR150s (I know -Open vs closed and all that). There's a clear step up in detail and better note decay.
Their only real flaw is that hiss with noise reduction on. Easily avoided if you use an adequate amp in passive mode and they make a fantastic set of standard closed headphones for the money.