Those of you who are saying Zero is darker than Feline are daffy. It's definitely got a helluva lot better staying power than Feline, but Feline is pitch black. The only other black pencil that's rivaled its blackness is Stila's Onyx, and even that has a bit of a brown tint to it when smudged- whereas Feline has an almost blue-black sensibility to it.
I was initially disappointed with these, they smudged the second I touched them and some of them have stupid silver glitter in them (and I'm generally not a glitter fan.) I realized that they had to "dry" for a few seconds and then they lasted like crazy, but the glitter was still offputting for me. The lip pencils, however, faded after a couple hours or so and didn't have the same intensity and lasting power as the eye liners. I think alot of MAC's Pearl Glide liners as well as MUFE's Aqua Eyes are more interesting and versatile.
I'll probably end up getting the Velvet Rope set, just to play with, but I'm pretty happy with my Feline- unlike so many of you it seems, I enjoy the smudgy effect it leaves.