I went to a friends house who owns the th900. So I finally got a chance to compare what I feel are the two best closed cans currently on the market. In short, we both were surprised that sonically, they are on the same level. Neither is really better than the other, just different.
The 900s have better extension at both ends, and have a slightly wider soundstage. But the mids are a tad bit recessed, not to the point where it's a problem, but they still are nonetheless. They are sightly bright, and the bass weight is just a little more than neutral. But again neither is to the point of being a problem, but one of the things that make them so fun to listen too. Both are colored, but the the 900s to a lesser degree.
I find the 3000s to have a deeper more 3 dimensional soundstage, better mids and more seductively tonality wise. The one clear advantage the 3000s have is the fact they actually isolate like a closed can. They each have their own little magic going on, and I was surprised by the fact the 900s weren't nearly as bass heavy as I though they would be.
I would pick the 900 over the 3000s for trance/techno, rock, r&b and hip hop, but would pick the 3000s for everything else. They both are on the same level when it comes to resolution and refinement. It's really a preference thing and I would be ecstatic to own either. I think David got it right when he ranked them right behind each other in his initial rankings. Although I would have ranked them both much higher.
. I loved how your's sounded at the meet! 
