There is no argument about the quality of Iroshizuku. Yama-budo writes like a dream in any pen or nib size. No feathering, beautiful shading, negligible show-through, not too wet and excellent lubrication, very smooth in writing. As with most Iroshizuku inks, water will immediately ruin your writing. Drying time is OK, almost 35 seconds on Rhodia.
Compared to other purple inks it's a bit lighter than Montblanc's lavender purple. Compared to Herbin's Poussiere de lune or Larme de Cassis, the ink is not only darker (more purple) but also a lot more saturated.
I like it best with a very broad and wet, or stub nib. I prefer the significantly darker purple that comes out then.
Written on Rhodia paper