Sometimes an unusual behaviour has just a simple explanation. Judging from myself I can say that the reason for our unusual, even annoying persistence with the NDH 30 is plainly their unexpected sonic quality, at least for their price. We all search for the best headphone our money can buy thus we constantly and happily share suggestions. Met with strong disbelief (understandable though) for what is very obvious through acctual listenings, our urge to share a rare finding was multiplied. Especially since some companies will have as believe that thousands of €/$ are required for their "expensive" technology. More so since too many years had passed without an offering that combined fine balance with top resolution and musicality. Now that such a headphone appeared almost silently, how can we remain silent and restrained? How can we not encourage other manufacturers to do their best for sensible money when a fine example has already been offered? Admittedly this is not the right thread and it is unfair for the fine HD-660S2, but this is where the disbelief was strongly expressed. Any detailed comparisons provoked will be good for all of us.
You put your finger on it. No one minds, we even appreciate, comparisons. Detailed comparisons even. Repeated comparisons too. But it's -- your word -- the persistence with which that headphone is mentioned that is starting to annoy people. I am not even active in this thread and still I've developed a low level distaste for those three letters and two numbers when merely catching up on the discussion.