I will try my best to help here:
Just how good is the bass quality on these ? How well do the handle upright bass ? When listening to techno and house does the bass have that sense of propulsion that makes the rythme infectious ?
The bass on these are best described as "neutral" or "natural", they have plenty of sub bass extension, and extremely high quality of bass, but in some sense they don't posses as powerful a "slam" or impact as other bass oriented IEMs (JVC/Fitear/etc). They will not lack bass when compared to a neutral sounding earphone (GR07/Etymotics), and these are definitely not bass lean. When compared to my TH600's (which can definitely contend with the best for bass quality and QUANTITY) they lack the raw impact and weight of bass lines that the TH600 are capable of, but then again the TH600's are more of an audiophile's "U" shape signature and the DITA's are a flat line (in my mind).
If you'd like a more specific comparison just PM me and I will be glad to head down to my local shop for more headphone testing :D
With jazz vocals and female vocals in general how engaging are they and how detailed ?
With details, female vocals, and jazz music, the DITA will both satisfy and impress, these IEM's excel at all of these, but I will say now that that without the proper tips, the treble can get a little sibilant, but not something you'll notice on jazz instruments, mainly on very high pitched female vocals(though infrequently) and the odd male voice. Details are maddening in a good way on the DITA, picking apart the songs analytically is wonderfully easy to do with the DITA, they're detail freaks, but in a very good way, not cold and analytical, but rather they're so transparent and natural in presentation that you will inevitably hear all the details the track has to offer, both good and bad.
Also, where are you guys buying from ? Through the vagaries of international currency rates at the moment they can be bought from Japan for about $844 AUD delivered. Is there any danger in buying through Fujiya Avic ? Hmmm tried ordering but it seems more complicated that at first glance.... back to DITA website.
For me, a local Singaporean I managed to get them at around S$629, with the Truth version available at S$999, from a local distributor. That converts to about $540 and $860 AUD respectively, but who knows how much shipping can cost you. Buying straight from the DITA sight would be the best bet though, less hands to pass through, less to go wrong.
For those of you with enough experience, How do these compare to other top of the line IEMs ? I am mainly interested in a neutral signature and looking for refinement, sound stage, layering, all the usual hifi requirements.
I have the unique pleasure to live in Singapore, a place filled with lovely little headphone/ hi-fi stores, and have listed to pretty much everything, from the SR009's to the LCD-X to the TH900 to the Fitear 335s, JH Roxannes, etc... Pretty much any headphone you could want to demo is available somewhere in the city and I've had the good fortune to be able to try all of these (:D), and I can say that the DITA phones are easily up there with the best of the best.
As someone else said somewhere along this thread, they sound a tad bit like the STAX house sound, that is to say lacking the magical electrostat mids, as well as the innate large soundstage that is characteristic of over the ear open headphones. There is nothing in particular in the frequency range of these phones that jump out at me, except the exceptional detail retrieval and transparency (I mean transparency, not perceived clarity due to a heightened treble, you can hear the singers licking their lips in between words), the level of detail is simply astounding, and the more I listen the more I love these IEMs for that. I can understand why Audionewbi compared them to the Etymotics, they are very, very detailed, much like the dear old ER4S. That said, unlike the ER4S which can be rather cold, the way the details are presented to you in the DITA are very different; In the DITA, these micro details are there for you to pick out, you just have to pay just a bit more attention, but when just listening the music is just so natural that it draws you straight into the music, and you forget the details, something in common with the SR009's when I demoed them for the first time. These are very near to a flat line in sound signature (at least the Answer version, the Truth I felt was more of a very slight U), and should satisfy any non-basshead. Treble is nice and airy, and extends very smoothly all the way past the human hearing limit, no severe peaking or sharpness (to my ears, but I enjoy a brighter sound).
Finger poised over
PRESS! (kidding, $999 is quite a lot of dosh, do think it through a little especially if you're looking for more bass, the Truth is a little more bassy than the standard Answer, but please don't feel like you're missing out on a whole different level of sound by getting the Answer, after trying the both honestly they're pretty much identical except for very very minor differences and a fancy cable.)
Hope this helps!