I bought this yonks ago and I must say, while it's far better than a pencil if you want it to last a lot longer, but for me - after a couple of hours, it starts to run.
I've only used the black so haven't managed to get around to any other colours yet, but maybe because the one I'm using is so old, the formula has changed.
I'm a big fan of winged liner some days and a smokey grunge liner other days so this liner is a great dual purpose. Easy to blend out to a smudged effect but will stay put once left for 45 seconds or so to dry and can also create a perfect clean black line for a sexy feline winged eye. I struggle with gel liners sometimes due to how quickly they fry out but when you know how to remedy this you're up and away :-) It's gentle on skin (my eyes usually burn when I apply liquid liner but not when I use this gel) all around a great product!
Tips: If gel is looking slightly dried up or cake like in the pot, seal it in a snaplock/glad bag (make sure the lid is on the liner tight!) and submerge the bag in hot water for 10-15 minutes, when you remove the product should be softer and will last for a couple months until you need to repeat this process.