Thanks for the accurate review. I have this ink, it was a gift and is my only iroshizuku.
Reminds me of one of the vintage Waterman Blue Blacks that turns a grayish-blue after a day or so.
I agree with this. I find this ink to really be a case of expensive-wine-tastes-better. Most comments regarding those grey blue-blacks refer to them as dull, and perhaps because they are called "blue-black" and are relatively inexpensive (my own experience with this was with a $5 bottle of Pelikan), we desire them to be more blue, or more black, or something other than the cold, nice-shading grey they are. With an iroshizuku in its lovely bottle and premium price tag carrying the name "fuyu-syogun" (Old Man Winter), we are more inclined to look closely at the grey and admire its subtleties. This is not a bad thing. I like the ink. I like to look at the bottle on my desk. It's a good thing. Expensive wine does, in fact, taste better.