The ink writes like a dream. It's not very wet, but smooth and extremely well-behaved in any pen. Just the combination crown mill vellum paper and a poster nib (as you can see), leads to some feathering of the ink. Drying times are simply fast, with just 12 seconds on this paper! Shading is low. Water resistance is low. Even after days it smears easily with just a tiny drop of water.
I called this ink a work horse. It is, and an expensive one. Even though it's wonderful ink, it's simply not special enough to justify the price. Yonaga (Sailor) and Baltic Memories (KWZ) are darker. Kikyou is quite similar to Iroshizuku's Tsuki-yo. And then Tsuki-yo wins. It writes even better and has wonderful shading.