I've been burning my D7000s in for several days now...probably on 60 hrs total...and since I replaced a set of D5000s with these, maybe I can comment with some authority.
The D5000 has, to my ears, a hump in the upper bass that makes a lot of my rock and funk sound *really* good. It also had a slight rolloff in the highs that I personally like. I am not big on "ear bleeder" headphones with ultimate extension up there, so consider that bias on my part. The downside of that bass hump is that, sometimes, I had that repeatedly-punched-in-the-ears feeling after taking off my cans. It was too much of a good thing on some music (even rock and funk), and got more noticeable as time went on. In addition to that, the low end extension is very muddy. Some people say "slightly"; I say "very". You only really noticed on music with a lot of complex bass, but I noticed and it is my major problem with this headphone. Mids were fantastic...bar none, great mids.
Okay, now to the D7000. Upper bass hump is GONE...yet I kinda miss it.
. I wish a slight, slight emphasis there remained, but I can't detect that at all. Highs are definitely not rolled off. Not harsh like the K701 or a Grado set, but right on the edge of too much. I am normally pretty skeptical of burn-in radically changing a headphone, but in this case I think time will smooth out the highs to where I appreciate the extra extension. But, at this point, I prefer the D5000 highs. Low end mud is history. I'm not sure if it goes any lower than the D5000, but it doesn't "woooom" down there like the D5000 did at times. (that's a technical term, heh) Mids are similiarly sweet like the D5000, but I think I like the D5000 mids a little more. (might be due to the extra upper bass thickness)
And Denon...can you PLEASE shorten the fricking cable? I can booby-trap the opening to my office with it and still have plenty of length between my head and my amp left over. Sheesh.
Bottom line...the D7000 isn't worth anywhere near twice the price of the D5000. It's probably the more accurate headphone, but the D5000 is just fun. Even if it did sound like an '80s boombox at times.
Pay yer $450 and be done with it, I say. Very nice.