It good but not great.
This does help to straighten out my hair but it leaves the ends frizzier than I would like.  I like that I can straighten my hair in less than 5 minutes.  It's easier and faster than with a curling iron but the curling iron does a better job.  If I am going out someplace special, I use a curling iron.  If I just want to do a quick straightening, I use this brush.
Rating: 4 stars