First, these are more convenient, more compact. I didn`t have to bother with an eyeliner brush. The fine tip allows for a really precise application, drawing fine lines, getting into the tiniest spots, really close to the lash line etc... You can thicken up the line by tilting the tip, sliding it across the lid. The tip is very firm, which can be harsh on the skin at times, but in exchange you get that amazing precision, which makes them unique for me.
Pigmentation is decent. Its not super intense, I would even call it sheer, but it dries fast and can be built up quite easily.
The product lasts really well, the entire day, 12-14-16 hrs with no smudging. Unlike some pencils or cream lines it doesnt melt thought the day with body heat, and it doesn't end up travelling, which is a huge bonus. The finish its somewhat glossy, and due to the nature of the pen, being so precise, you need a very steady hand, otherwise any little imperfection can stand out. Mac Fluidline in comparison is more indulging, it can be corrected and smudged, while these eyeliners are less forgiving; once they go on they stay put.
Although on me they are water resistant, they come off easily with a oil based cleanser, or, in my case... plain olive or avocado oil. I did notice some staining on my lids, but usually by the time I was`h my face in the morning it`s all gone.
Some of the pens come in `Ultra Fine`tip while some are `Fine`, with a slightly thicker tip.
Overall these liners are pretty good. I like them and have been reaching for them more and more. I guess it just depends on what I am going for. Like lipsticks or eyeshadows, eyeliners come in a variety of formulas and they all have their bonuses and/or minuses. You just need to try them out and see which one fits your needs, figure out what you`re looking for and what your are most comfortable with.
The 3 I have here are Very Black( ultra fine tip), Olive and Teal (Fine).
Fine and thicker swatches.
You can get these in most drugstores.