Please, fellows, please. Where's DUNU
Like you I had a vested interest in what Dunu had to offer. I had a little time (~10 minutes each) with them in the LMUE booth. Source was AK100ii (known to be neutral, transparent, slightly bass-light). Teo reminded me that they are prototypes and not the finished product. So just take these preliminary impressions as just that.
DN2002: The most accomplished of the bunch. Slight W-shaped sig with bass emphasis, treble detail and a bit vocal forward. The dynamic bass was lovely. Good slam and natural decay, very little or no bleed into the mids. Treble detail is very good and smooth. Narrow stage. The most coherent of the Dunus I auditioned.
DN3001: Treble-heavy, and on the brighter side of things. Bass is very fast with a much lighter punch than 2002, I thought the sound wasn't very balanced and sometimes the treble can be peaky and piercing. Maybe great for detail-heads but I couldn't wait to change to another IEM.
DN4001: It has the airiest sound, and widest and deepest stage of the three. The bass reminded me of the 2002 bass. Natural, bloomy, great authority and just the right amount of decay. The 4BAs, work in tandem to produce a sweet, detailed sound, without the harshness of the 3001. But here's the thing. I felt that the DD and BAs were each doing their own thing. Not very coherent. But Teo did mention this is still some time away from being the final release product, so I hope to see this improved. Much potential to be a contender though.
Hope this helps in the slightest. The 2002 was apparently the meet favorite with many people liking it.
EDIT: For comparison's sake, they do not reach the standard of FLC8 yet.
EDIT 2: Teo from LMUE: SUPER nice guy. My first line to him was, "hi! I buy your stuff!"