Finally got the warranty replaced DNK back. Did a quick listen to check if they work before I post them for sale and that gave me a chance to A/B them with the W30.
Bass of the DNK is definitely more powerful, especially in sub-bass region. There is a strong rumble that is not as prominent with the W30. I'd say slam and midbass is similar between the two but the Westone's is slightly more textured and detailed. The Dunu sounds warmer, even though is's v-shaped. For mids and highs the W30 takes the cake, especially in the highs. While the Dunu is has a near-sibilant peak at 8-9kHz, the Westone is smooth and more transparent. The Dunu is a bit easier to drive - about 80% of the volume on my X1 needed to achieve the same loudness level as the Westone.
I'd say if you like genres like dubstep, hiphop, house, trance, where the bass rumble is more important than treble detail, go with the DNK. For guitars, metal, vocals, rock, classical, jazz I would stick with the W30. Obviously the W30 costs twice as much as the DNK so for most people I'd say the DNK is the better choice, especially if you're not sensitive to sibilance.
The W30 grew on me faster than any IEM I've tried to date, not only because of the sound, but also the comfort and the detachable cables. So even though I will somewhat miss the lows of my DNK I am selling them here:
http://www.head-fi.org/t/754081/fs-dunu-dn1000-brand-new-warranty-replaced-a-ton-of-extra-tips