I ordered this ink based on the rumors that it possessed a special quality. Even at the Goulet Swab Shop, you can see the rumored "red sheen". Now, I haven't quite gotten that effect very much in person, though I have gotten it to show up in SOME macro shots I have taken of this ink. I may have been disappointed in this ink because it wasn't as multi-dimensional as I had hoped, BUT... I love the color!
Most people would think "Ebony Blue" would denote a very dark blue, blue-black, or midnight blue color. I didn't find that to be the case with this ink. To me, it is a very dark teal. There is some green in this "blue", and personally, I like that. I'm a big fan of teal, but Private Reserve Blue Suede (another misnomer) is a bit too bright for me to use this time of year. Of course I say that, but I currently have Iroshizuku Tsutsuji and Noodler's Dragon's Napalm inked up, ha!
ANYWAY- This is a nice ink, despite the shyness of its red sheen. It seems a little dry in my Lamy Safari, but most inks do. It is dark enough to be used professionally, and would add a nice touch of personalization to your work. This ink screams "I am unique and came from a fountain pen". I expect that effect would be exaggerated if you could find a wet enough pen to show off the red aspect. Ebony Blue is not waterproof, but wasn't the worst performer of those I have tested.
I would most certainly recommend adding this ink to your arsenal, particularly if you are a fan of blues, greens, or blue/greens!