I've not really tried gel eyeliner before so thought I'd pick this up - it comes with the gel and the brush applicator so I thought it would be a good starting point. I'm an eyeliner fiend but I tend to either use a liner brush and black shadow or a liquid liner pen. Sorry for the stock photo by the way, I managed to clag everything up before I remembered to take a photo.
Overall, I didn't really like this. The pros were: it's a really intense black and lasted well throughout the day (though there were a few little "crumbs" that flaked off during the day), plus doing flicks at the end of my lids was quite easy. The cons: the brush really (or maybe my technique), it felt a bit hard/stiff and I found it a bit difficult to do thin lines on my eyelid. My eyelashes are short so I like daytime eyeliner to be quite thin so you can actually see my eyelashes - trying to apply this thinly looked a bit odd and patchy like I'd applied it with a toothpick or something.
I wouldn't repurchase this mainly because I didn't like the brush, I'll continue to use it for nights out but probably with a different brush - I think I do prefer the look of powder or pen liner though. If I did purchase a gel liner in future, I'd purchase that and the brush seperately so I could do a little bit of quality control brush-wise.