The AD2000 is a great headphone, full of air and detail, yet very fast, a near perfect rock headphone. It does lack bass quantity, however, and that is where the AD900x comes in. If I can get around to saving some funds, I wouldn't mind trying out the AD2000x, even though at least one user of the AKG K702 65th anniversary edition, which I also have, have claimed that the two headphones are to close in SQ to keep both, he sold his AD2000x.
I'll add that I have been listening to my AD900x much more than the K702 anni's.
And yes, I am selling my AD2000's in the for sale section, as you can see from below.
I assume your referring to me about selling the AD2000X. I never sold them, I had them for sale but actually just withdrew the sale. I just can't bring myself to sell them right now. I realized I made a rather amateur mistake when listening to them. I remember reading awhile back on a W3000ANV thread about how users needed to furiously bend the headband to their head to get a proper seal. Well, it seems the same applies to the AD2000X, at least for my head.
I did some more aggressive bending and then probably 90% of my original complaints went away and I suddenly "got it", the "magic" of the AT mids so to speak. Before I found them very fatiguing and congested and I was just very underwhelmed overall. Now they fully meet my original expectations and I really don't want to sell them. But I also love my K702 65th equally as much, just different flavor, I still find the K702 65th more neutral, natural, and well balanced and with greater bass quantity and possibly quality, though the AD2000X bass is subjectively "faster" to me. I'd still say they're both in the same class but the satisfying enough and unique enough for me to keep both.
Only reason I wanted to sell anyways was I wanted to try an HD-800. Now I'm trying to work with the seller to see if he'll let me split it in 2 payments. If so, I'll have all three to compare by late March.