Fantastic!
Noodler's Walnut is fantastic!! It's bulletproof, but writes like any other ink. It's a great, rich, brown colour (the swab is a accurate), and I use it all the time. I've used this ink in fine nibs, and bold nibs, and it's great with any nib size. Unless your workplace has an obsession about black ink, I think it would also be an excellent work ink. I would never be without it. I import it from the Anderson's as you can't buy it in the UK, and it still works out cheaper (inclusive of the postage, which is cheaper than elsewhere) than buying the few Noodler's inks that are still available here, as long as you buy one bottle at a time to avoid triggering customs duty.