Reporting back with my D2000 / D7000 comparison results.
Equipment:
Oppo BDP-83 > Objective2
Logitech Squeezebox Touch > Objective2
Music samples:
Redbook CD:
Diana Krall "The Look of Love"
Miles Davis "Kind of Blue"
Gustav Holst "The Planets" (Dutoit - Montreal Symphony Orchestra)
BluRay:
Legends of Jazz: Showcase - Ivan Lins "The Island"
SACD:
Bucky Pizzarelli "Swing Live"
DVD-A:
Dishwalla "Opaline"
16/44 FLAC:
Paul Simon "Graceland"
Fleetwood Mac "Rumours"
Supertramp "Crime of the Century"
Hugh Masekela "Hope"
I listened to the D2000 and D7000 back-to-back in a sighted listening comparison first, then switched to blind testing.
Under sighted conditions, I was able to identify clear differences between them in a relatively short time. When I say "clear differences," that is in the context of being an audiophile - a casual listener might not notice the differences between them without someone pointing them out. My findings?
Bass is definitely stronger on the D2000 - it hits harder and blooms bigger. Some people might be attracted to this with some genres of music, but to me, the bass bleeds into the mids a bit and places a thin haze in front of the overall sound of the D2000. Mids and Treble on the D2000 reproduce the same frequencies as the D7000 (in other words, no details are missing), but the mids and highs seem like they are slightly recessed to me compared to the D7000. To be cliche, the D2000's sound like they have a "veil" in front of them while the D7000's are clearer and cleaner sounding. Bass on the D7000 doesn't hit as hard, but it is better controlled and more even with the rest of the frequency band (although if I'm honest, the D7000's are on the bloated side too). Listening to the D7000's, every voice and instrument sounds like it is in sharper focus in comparison to the D2000, where images are slightly softer. If it were a TV image, the D7000 would be 1080p BluRay and the D2000's would be an upconverted DVD - very good, but not quite as sharp.
The more I listened, the more I suspected that the D2000's bass was the cause for all of the other characteristics. I didn't hear any details missing from the D2000's, it's just that they were a little softer and further away. It was subtle though. Again, a casual listener might not notice any of these differences.
Once I felt I had a good grasp on the differences between them, we switched to blind testing. There's not much to tell though - I was able to identify the D2000's and D7000's every time.
As to whether the D7000's are worth paying 3X the price of the D2000's...well, that's up to the individual. If you're a starving student and want a pair of Denons, the D2000's certainly deliver 90% of the sound quality of the D7000's, and if you never listen to the D7000, you won't know what you're missing. On the other hand, if you can comfortably afford them, the D7000's are easily worth the price of admission in my opinion. After conducting this comparison, I know that I personally would not be happy with the D2000 after owning the D7000.