I am a gel or pencil girl and typically do not like liquid. I should preface this review by saying that I am also not good at applying it.
This is actually the messiest application of any liner I have used, but i use it anyway because it is head and shoulders above all other liners. It catches on my lashes, difficult to put it where intended, and makes a big mess. I could never do a clean line with it. I've gotten better about holding the wand horizontally and just pressing into the lash line. But sometimes when it appears to be going on right, it is still a jagged mess.
The formula wears better than anything I have ever tried. It is smooth, intense black and can really reshape your eye beautifully. There is nothing else like it. It stays on all night and then some, without smudging or fading.
I don't like to spend more than 5 minutes on makeup. To put this on fairly quickly, I try to dot this as close to the lashline as I can, but most times I will mess it up. I just run my finger over it to work it into the lashline, with makeup remover inhand to wipe away the excess. If I mess up really badly, I'll just put a swipe of eyeshadow or soft pencil over the line to blend it. Alternatively, I'll just run my gel liner brush along the liquid wand and apply it with that. Once it's on, it stays all day. And it is almost like semi-permanent makeup because if I don't dutifully scrub off every last bit, then it is still hanging around days later.
This is 100% reliable for me even in the most humid weather when my gel fades and smudges. I can't say that about any other product. I think of Mac as one of the 'harsher' brands in terms of ingredients and what I want to put on my skin every day. But this actually doesn't irritate my eyes or cause any of that black soot build up in the corners (even when worn for days longer than I really should ;)).