Noticeable differences--check the review.
Benefit is $22 for 1ml & NYX is $9 for 1ml. Benefit has a felt tip & NYX has a brush tip. I feel the felt tip gives you more control during application. NYX is a good eyeliner however it does bleed a little when using so you have to be very careful. NYX wouldn't be a good liner to start out with if you're new to liquid eyeliner. Personally, I find Benefit to be easier to use. Both products last all day without smudging. Benefit is a matte formula while NYX is not. NYX has far too many differences to be considered a dupe for Benefit however both are decent products depending on your preference.
I would absolutely agree with this review! NYX glides quite well. Thank you for saving me money.
Both have their strengths and weaknesses but I reach for NYX more often. It’s has a smoother application and doesn’t seem to skip as much as the Benefit, which also seems to dry out faster while applying and does not seem to be as wet so the ink is less opaque, but it does have a matte finish vs. the vinyl finish of the nyx liner. The NYX liner also lasts foreverrrrr.