I have used Lancome, Urban Decay, and Make Up For Ever waterproof eyeliners to name a few. These were all twice as expensive as the GOSH eyeliner, yet the quality wasn't better. I actually find GOSH eyeliners to be better than all of those!
Very creamy, actually stays on (i have a hard time with keeping eyeliner on my waterline, even waterproof ones! and this one worked on me).
The only setback is that once you get to the last few inches, it is very difficult to sharpen the pencil to a point that it doesn't hurt you. Perhaps that is just a poor sharpener though :) A keeper!

Gosh also makes a great eyeliner called Velvet Touch Eyeliner. I'm excited about this because my left eye seems to be somewhat sensitive and it exhibits this characteristic by tearing up every time I try to apply eyeliner. This pencil solves this problem in two ways: first it is waterproof, so no smudging, the other is that it is soft and easy to apply. With minimal pressure, the colour goes on with a creamy finish due to the Vitamin E and Jojoba oil used as ingredients.