As a rickety old weirdo slash goth I've been wearing supermassive eyeliner since before half of these reviewers were born- lol - scary; I really can't think of a brand or format I haven't tried. That being said, I've somehow managed to avoid MAC fluidliners up til recently, mainly because I've had just about enough of spending $$$ on products that virtually desiccate in the bottle before your eyes. By now I can use a formula once and tell you how long before it ends up as a dry black lump. Handled with care, and because it is denser and less laden with volatiles and alcohol than many others, I can tell that this formula has a decent lifespan, so I am confident on that account.
Great tip- use a little boiled water to refresh your cakey/drying mascaras and liners. They're still going to die on you, but you'll get another month out of them.
The pigmentation is 8/10- there is a slight translucence, but I find this useful when you want a more modest effect; many other liners are completely opaque and don't allow you to develop shading and nuancing. So to me this is a plus.
The colour itself is eyecatching without being eyef*cking; you don't feel like a 15 year old UD glitter victim. It is a smoky dark stained merlot and I don't see much sparkle in the finish at all. I have large green eyes with gold and ochre speckles and while it is complimentary, it is not super-contrasty and thus not a LOOK AT MY EYES type of situation. More of a 'consider my beauty holistically' effect ;-) But I'm someone who has worn inch wide UV red liner to the supermarket so perhaps my terms of reference are quite erm... broad. If you've only ever worn black liner this may still be a bit of a shock to the system.
The wear is among the best I've experienced, and I don't say that lightly, because I have oily lids and wrinkles and I am a chronic eye-toucher. But it comes off easily just with your usual cleanser. The only product I've used that would better it wear-wise is an old Dior liquid liner I forget the name of now- I use to put that on at noon and it would still be solid 24 hours of partying later. This one comes close.
There is no grit, no wandering greasiness, it gives you a little time to work it if you want smudge and I get around 2 hours on the waterline, which is fine- there's very little that will actually stay put there unless you want something resembling industrial floorpolish crusting up your eyeballs.
So overall this liner gets both thumbs up; there are no downsides or major issues and it is a solid investment.