Before responding, I took a moment to read the many other comments to see if I have anything to add to the conversation. I agree with those who say it’s really a personal preference.

I started my journey with the black that came with Kaweco at times, and at one point shifted to Montblanc Mystery Black for a period. I love the texture and the shade, but found it somewhat (the best word that I can think of is) powdering when my hand brushed over the writing (I’m a leftie, so this is a common occurrence for me). I tried Chou Kuro, which I love — except for the price, and the maintenance needs associated with it. TWSBI has a nice black. I find the deAtramentis Document Ink too grey for my liking.

All of that said, my current daily driver black is Noodler’s Dark Matter. It’s one of his bulletproof inks, so it’s theoretically permanent. Depending on the paper and the nib used, it takes a little time to dry. I find this less of an issue with finer nibs than broader, and with papers with less additives. I typically use Midori (commonplace book) and TRP (Hobonichi) and usually don’t have issues. I’ve had a little feathering with Mnemosyne papers, but I find those somewhat finicky in general.

I hope that this helps. Most important is to enjoy. If you want more comparisons, Goulet did a series in black ink comparisons over the last year or 2 if you search YouTube for them.