oh I don't know. I guess I was hoping it would help keep breakage away. It doesn't do that. It doesn't offer much support at the line of demarcation either. My hair is smooth and I do not suffer from excessive breakage, but I don't want ANY broken strands (unrealistic I know).
What I have noticed: at around 5-6 weeks post I'd start suffering from chronically dry and crackly looking ends. I mean crunchy dry, especially when I'd take down my bun and my hair was already bent from being in the bun. When I'd finger detangle, I'd have short strand broken hairs and bent hairs.
When I started using Redken Anti-Snap (off and on since '02), the severity of this problem was alleviated slightly, but not completely. I was doing HOT w/olive oil and had good hair practices but I still had this problem.
It wasn't until I started using rice bran, meadowfoam seed, sunflower, hemp seed, and a few others that I noticed - the pliability of my hair is completely different.
Leave-ins are an option, but not necessary
I don't suffer from dry ends anymore.
I hope it helps.