Believe me I was hoping that this headphone would not be better than the other phones I listened to as I could not really afford it. I had all day to try out most of the best high end phones available: Abyss AB1266, Stax SR009, Audeze full range, Sennheiser HD800, AKG812, Fostex TH900 and Ultrasone ED 8, 10 &12.
In my opinion the Edition 5 was streets ahead of every pair, with the exception of the Stax and Abyss. Against these two the ED5 won out because it was more versatile musically, and because it could be driven nicely by my AK240.
On the second day I was listening to the ED5 with a musician who thought they were streets ahead of the Stax and said they were the best he had ever heard. Fundamentally what the ED5 does that no other phone does is create a sense of space. Not space in a soundstage sense, but space in the sense that you are not wearing anything on your ears. Almost as if the ED5 is positioned a couple of inches further out from your ears, difficult to describe the experience unless you have heard them - or are more gifted in describing these things technically than me. In this way they are absolutely extraordinary. But I have to stress that my wife who is not an audiophile by any means but has excellent hearing, preferred the Audeze LCD3. So it seems everyone may not experience what I did.