The regular Pilot black used to be my only ink during all of the time I used cartridges.
It isn't the darkest of blacks, but dark enough for you to not think of it. And it isn't the fastest drying ink, but fast enough so you don't think about it.
I was very happy with it back then, not sure if I would be today. And I probably wouldn't want a full bottle of it. But for cartdirge ink it was really good