I don't think that the lash extension effect it's supposed to provide is all that noticeable. I think a similar look can be achieved from most mascaras. What I do think this mascara excels at is seperation and natural volume. When you wear this mascara, it gives you the look of naturally lush lashes. It doesn't provide ridiculous volume or length so I usually use something like Diorshow when I'm going out but this is my go to for everyday eyes.
Here are some pictures with and without the mascara on:
I also really like this mascara for the bottom lashes. I usually never bother to put mascara on my bottom lashes because they would get weighed down by the formula of the mascara or the brush would end up putting product on my skin. With this brush and formula, that is no longer a problem. This is mainly because the brush is really thin but has a lot of bristles so it doesn't clump your lashes together and it lets you get to all those hard to reach lashes.
The only cons about this mascara would be the amount you get for the price you pay. This is a pretty small mascara compared to others of a similar price. Also, I've read that the mascara tends to dry out fairly soon after opening. I haven't noticed this to be a problem thus far but apparently others have noticed this after about 2 months.
All in all, I really like this product. I think that because it doesn't go on overly thick, it's a good mascara to wear underneath other more thickening mascaras if you're going for a more dramatic look. I especially like to wear this under other mascaras that I struggle to get good lashes with on their own like the Givenchy Phenomen'Eyes or the Covergirl eyelights mascara. This is definitely a must try in my books. Go out and give it a go!