This is a fantastic serum. I was going back and forth between this and the Reversalist serum which also has great reviews. I ended up getting this one for $13 from eBay, which quite frankly influenced me to get it. I'll have to say it was worth every penny. I love how this makes my skin look and feel. I occasionally get a few bumps here and there from clogged pores. I've been using this for 2 weeks and haven't got a single one. My skin is so much smoother and I swear my pores are smaller. I use this in the a.m. under my Skin79 BB cream which goes on much smoother. Then in the p.m. I use it underneath my Neutrogena Ageless Intensives Deep Wrinkle Night Cream. I was worried about using this underneath a retinol product but I have had no sensitivity. As far as the packaging, the bottle looks nice but I'm not crazy about the dropper, a smaller one would have been better. I would like to try the Reveraslist serum at some point but I would definitely buy this again.
EDIT: After using this for 2 months I have not had a single breakout. This stuff really is fantastic. I use 2x a day and still have 1/2 bottle left.