I bought the black version of this eyeliner. After having eyeliner from big and small brands, this truly amazed me.
You were able to fix a mistake you made with it immediately, but afterwards, it wouldn't come off until you used eye makeup remover on it.
It doesn't smudge at all, and it's truly waterproof (I did a test on the back of my hand).
Even with it's amazing pigmentation, it's not stubborn to take off with make up remover, making it the perfect eyeliner.
The only con of it would be that after sharpening, you'll have to go with a bold eye look since the tip becomes chunkier.