I got a few samples of Eyeko eyeliners free from work and it was perfect because I was dying for a new liquid eyeliner that suits me.
I hate using regular liquid eyeliners as I find they're far too messy and I don't have a very steady hand. I loved this eyeliner as it was more like a marker or felt tip pin and was so much neater. It also claims on the box to not smudge or smear and after testing it out multiple times I can say it certainly lives up to it's claims.
After wearing it out the only parts that smudged were the flicks on the outside of my lid and they still faded evenly so I didn't have random black smudges everywhere. Not to mention I have a terrible habit of rubbing my eyes and it barely smudges at all, it's not even noticeable if it does.
There was one problem with it unfortunately. I found that the pen wasn't moist enough and dried out very quickly, which was a huge downside. At least with regular eyeliners you can dip it back in the bottle and it's no longer dry.