I'm like one of the biggest Flat4 fanatics on head-fi. I have the SUI and KAEDE, and while the latter is a gorgeous piece of kit that is definitely an upgrade in the materials department, I'm not so sure it's a big upgrade in terms of sound. In fact, it sounds quite similar to the SUI to my ears, main difference being slightly less glare up top and slightly more bass heft below. While I appreciate the better upper-end, I don't think the SUI needed anymore bass! The KAEDE can be a little overwhelming on certain tracks. But really, both are exquisite and beat the pants off of most other IEMs for me personally, especially in terms of refinement (no nasty resonance), detail extraction, and dynamics.
As for the Donguri, I hate to say it, but they kind of remind me of those awful Thinksound RAIN earphones on the outside, though I'm sure the craftsmanship is superior. Knowing Ocharaku, the engineering on the inside will result in a good sound too.
Edited by MuppetFace - 2/10/13 at 7:35pm