I enjoy this tubing mascara a lot. It doesn't smudge when I wear it for a short amount of time, but if I do it all day, I'll definitely see some darkness and tubes under my eyes. I use a primer/fixer that largely eliminates this issue for me, thankfully.
I get nice separation and length which is what I'm looking for. The formula is pretty liquidy so I do have to be mindful about scraping off excess, otherwise it's too much for my tastes.