I love this brush! From now on, it's only 100% boar bristle for me. I have fine, thick, wavy hair and this is the best brush I've ever owned.
Have you seen those old movies where the woman sits at her vanity before going to bed at night and brushes her hair many times? Now I know why. When brushing from root to ends with 100% boar bristle, it massages the scalp and distributes the oils all the way down to the ends.
I have long hair with dry ends, but this has turned my hair to normal in a short period of time. My hair is shiny. This is a round styling brush, so I'm going to order the Denman brush for regular brushing. (It's way cheaper than Mason-Pearson.)
I'm not sure if these bristles will work on every hair type, but it's great for me.