I'll update this after using it longer, but I had to write a first-impressions review because this stuff is amazing.
I avoided trying the regular or waterproof versions of this stuff for so long because I'd heard it was a dupe for Better Than Sex which is one of my most hated mascaras ever (it was a clumpy, flaky nightmare). But, I was desperate and needed a waterproof mascara fast, so I crossed my fingers and prayed I wouldn't have a reaction to this one as I bought it.
My lashes are kind of sparse, are normal in length (maybe a tiny bit long-ish), point straight and down (a mix of both on each side), and almost never hold a curl. But this stuff? It keeps my curl all day. I think the longest I've worn it is 14 hours, and my lashes still looked fake when I took my makeup off that night. I've never had a mascara perform like this one, and I've been wearing mascara for almost 20 years. They're thicker, longer, and not gross-clumpy (this does kind of clump, but in the good way, not the way that leaves you with like 3 giant lashes because they're all stuck together). It seriously looked like I had false lashes on.
I have this in Blackest Black, and it is a very black color, which I love. I also think it can be built up with two coats, but I think after two it would be a clumpy mess.
The two downsides I've found are that it's really hard to remove (I've tried a cleansing balm, cleansing oil, eye makeup remover that usually works for waterproof stuff, and micellar water), and it does flake a tiny bit. Next time I wear it, I'm going to try a little coconut oil to remove it, which I think will take it off easily. The cleansing balm and oil both worked, but I had to really work the balm into my lashes for a long time before it all came off. The flaking is not super bad, and I didn't even notice it until I leaned in close to a mirror. Usually, if a mascara flakes, it gets in my eyes and they get really irritated from it, and I'll have big flakes all over my face. With this one, it was a few teeny tiny ones, right below my lower lash line, and they were easily swiped away with a makeup brush or my finger, without it messing up my makeup.
-super black color
-holds a curl all day
-mega volume and length
-nice brush shape (kind of hourglass; not too big)
-looks great on my top and bottom lashes (one coat on bottom, two on top)
-hasn't irritated my eyes so far
-dries pretty fast
-I think you could probably swim in this and it wouldn't budge because it is super waterproof
-despite being difficult to remove, I haven't lost any lashes while taking this off like I usually do with stubborn mascara
-formula isn't super wet or dry (it kind of makes me think "mousse")
-doesn't make my lashes feel crunchy and dry
-very minor flaking (almost un-noticeable and easily wiped away)
-you probably should use an oil to remove it, because once it's on, it is ON and very hard to remove