I have a pair of AH-D7000s sitting here next to a pair of TH600's and apart from having different pads between the two, you'd have to have super ears to tell them apart quickly. They produce similar sound levels, similar tone balance, they use the same drivers, pretty much identical cords... they're basically the SAME DAMN THING. housings are different. wheeeee. tiiiiiniest bit of more warmth to the d7000.
I wanted them to be super-different, because I'm a HUGE d7000 fanboy, buuuut. um. >.> they're pretty much the same. I think the d7000s might be tuned differently, too.