I've been posting on /r/fountainpens fairly regularly to report my progress on using whole bottles of ink. As the threads start to multiply I thought I would consolidate my impressions here. I'm still designing this site and plan to make a nicer layout, more consistent decriptions, and add some pictures in future.
Kyo no Oto Nurebairo
Best Ordinary Black: Aurora Black
Best Permanent Black: Sailor Kiwa Guro
Best Black With Personality: Pilot Iroshizuku Take Sumi
What about xyz black?: I only rank inks that I have finished a complete bottle of.
The first bottle of ink I ever completely finished. Take Sumi is forever something of a gold standard for me, it's just so lubricated and snooth to write with while not being pure unrelenting black. It shades a little, and seperates into blue-greys that make for great sketches.
Beautifully matte, completely permenent, but extremely tempermental. If you're not feeling like regularly cleaning your pen you can step right off.
There are few inks that flow as well as Aurora Black. It writes every time with a pure, clear, black line. If you want a no-muss, no-fuss, awesome black ink this is the only one you'll ever need.
I didn't think this was an amazing ink, which is weird because most people on the internet seemed to love it. It's greyish, and so dry it just didn't write in some pens. And it's an extremely stupid bottle. Best I can say about it is that the bottle is small.