First, I hated that I had to buy a separate brush for it.
But the MAC gel liner is really, really thick and dense and inky. Could be a bit dramatic for daytime wear if you are heavy-handed. And IMO it's not easy easily correctable bc it's so thick and the color is so saturated.
And then, you have to load sooooooo damn much of it on the brush just to create a decent line. But it seems like gobs of it are always left stuck in the hairs. If you clean it, then you waste LOTS of product. But if you leave it, then it dries hard and you can't use the brush the next day. It leaves the brush like a knife.
I have a steady hand and I am good w/ liquid liner. But I found MAC gel liner to be really hard to work with. And when you think about the cost of it, plus the cost of the brush, and the cost of a cleaning solution to clean the brush everyday, and factor in how much product you waste, it just turned me off fast.
Whereas, this Revlon stuff is about half the price, comes w/ it's own brush, the product is creamy enough that you can wipe it right off of your skin or excess off the brush (if you do it w/in the first minute or so). I've been leaving excess product on the brush anyway, and it doesn't cake up. And the color is more subtle...which is good for me bc w/ MAC gel I'm sometimes walking out looking like a drag queen.
I ike the MAC eye pencils and liquid liner, tho.