I would absolutely put them above the Denons. They image better (it's "small but good" compared to the usual suspects in the open-headphone world), feel better put together, and don't rattle/thump/boom on the low end. Detail is as good as anything in the price range (if not better, depending on what we're comparing - this does include open headphones). Comfort is good, fit is good, they will get hot though. The pads also seem to need to break-in within the first few weeks of use (out of the box mine were fairly stiff, now they're glove-soft; this happened very quickly (within a few days of normal use)). They are probably among the heaviest headphones (390g), Koss dynamics aside, that you'll likely want to listen to.
They don't seem very picky about amplification - they sound universally good out of everything I've plugged them into (nothing portable though - all hi-fi systems and headphone amplifiers); they're efficient and low impedance.
They are not a "fun" headphone like the Denon - they do have very deep reaching bass (I would not say "more bass than anything" though - the HFI-2400 has more bass), and it can hit fairly hard, but the mids are really what they "do". I would suggest them for some electronic music, anything with strings/keys, jazz, slower paced music, or anything that you want to listen to with a "big disco sound" (the comments about them making tracks sound "heavy" I would agree with). They do well with movies and videogames as well, but may make some sound effects larger-than-life (for example explosions take on a very "end of the world" tone). I do not consider them a "this genre only" type of headphone, despite the genre list, they can do all things fairly well. That having been said, they are shown-up by some similarly priced open-backed models (e.g. AKG K701) in terms of speed/finesse (whatever you want to call it), but they don't impart a "boom'n'bloom" feel to music as many headphones that can produce "lots" of bass do (e.g. HFI-2400).
It was either in this thread or another thread, that a poster said they considered the KH-K1000 worthy of sitting alongside the likes of K701s, HD600s, and similar - I agree with that statement. The trade-off is long-term (6+ hours; however having said that, I have worn them for 7-9 hours in a single sitting without adjusting them once) wearing (heat + weight; if this doesn't bug you then so be it), and "spaciousness" of the soundstage. They can also exaggerate a bit with bass notes, but it's not unruly. And keep in mind, I'm not a basshead/basslover - I have no idea how these compare to more conventional "bass headphones" like the Sony MDR-XB or whatever else; they may not exaggerate the bass in your view, depending on what your view is (from my perspective, MDR-F1, K701, and the Koss ESPs have adequate bass - that's probably "bass light" to most people).
There's a Japanese review you can read here:
No idea how accurate the FR graphs are - they seem to put them in-line with the L3000 in terms of bass response (and from what I've read, the L3000 is supposed to be some kind of monster, even this thread puts the K1000 up as some kind of Swing King in the LF; again, I found the HFI-2400 (which is an open-backed headphone with a smaller driver) to push more bottom end).
Take it for whatever it's worth.
Oh, and I'd entirely suggest the AudioCubes route - it will take probably two to three weeks depending on where you are (they state that the K1000 is a special order item), but they're very easy to deal with, and everything arrives as it should.
Originally Posted by AzraelDarkangel
My impression from reading the thread is that they may have more potential than the D2000/D5000, particularly from a good amp and better cables.