Overall, I'm fairly impressed.
One of my favourite eyeliners ever is Avon's Ultra Luxury Eye Liner and I think the last time I bought one it was $5.99. However, since they've discontinued my favourite colour (Hunter Green), I haven't bought one in a long time. I was so devastated about that because it was the perfect green: a kind of forest green. It wasn't too bright or olive, but a dark liner that was only just noticeably green, with a lovely sheen - not shimmery, but it had a satiny look it. Anyway, it's time to let it go.
So the Glimmersticks Diamonds liner is a different texture to the Ultra Luxury liner. It's not as soft, so you need to go over it a couple times when you apply it. On the other hand, the one problem I have with the Ultra Luxury liner is the fact that it smudges, since it's so soft. The Glimmersticks Diamonds didn't smudge on me at all. Hooray! It's not as black as some other liners, however, which may be a drawback for some. Personally, I have plenty of really black eyeliners, but few that are sparkly and don't smudge.
This one draws a great, thin line, which you can obviously thicken if like. The glitter is really subtle and gives a really flattering hint of glam. If you're after something with tons of sparkle, then this isn't the liner you want. The glitter is really fine and appears to be in a number of different colours. I found that smudging it made the glitter more apparent. Since the glitter particles are so fine, and therefore tightly packed in I guess, smudging it spreads out the glitter and makes it sparkle more. The actual black liner itself hardly budges, but the glitter spreads nicely.
Ugh. Is the back of my hand really that hairy? Sorry about that. The left is the liner simply applied as normal. The right line is smudged slightly. It's kind of hard to tell here, but the glitter is definitely more obvious on the right in real life.
I also love the fact that it's retractable. That means no sharpening is necessary (who doesn't love that?) and when you're done, you can just wind it down and not accidentally smush the tip when you replace the cap. Or is that just me? It also means you can see exactly how much liner you have left. Why have I never used a retractable eyeliner before? This isn't a magical new invention or anything. Anyway, the one thing I despise about pencil liners is when they get too small to comfortably hold when sharpening the damn thing, as well as getting a good grip on it when applying it.The only real problem with the Glimmersticks Diamonds liner is that it's not really an option for use on the waterline. For a start, it's not very black, so that sort of defeats the purpose of applying it to your waterline. It's not very soft, so if you persist in applying it there, it takes some effort (and for heaven's sake, be gentle!). I'd also beware of using it on the waterline, since there is glitter in it. It's probably not a good idea to get small particles of the stuff that close to the inside of your eye.
Overall, I'd suggest giving the Glimmersticks Diamonds eyeliner a try. It's really quite cheap and long-wearing, so it's a good investment if you want a subtle sparkly liner. Then there's the added bonus of being retractable. I love it.