I was a bit skeptic when I bought this brush. Originally, I thought that it was self heating, etc. Sadly, it's not (that would be lovely), but it is a fantastic blow-dry brush. I have insanely curly, thick, and frizzy hair (a few inches past shoulder). My typical straightening routine is blow-dry with comb, then blow-dry with brush, then either flat-iron or curling-iron straight.
While this brush did not leave my difficult to tame mane perfectly straight, it did result in a straighter blow-dry than I have ever gotten before and with significantly less effort. I could see the indicator bands change as I did my hair and enjoyed the square shape of the brush (all of my previous brushes have been round).
The only reason this didn't get 5 stars is that the bristles did not stay perfect under the heat but instead melted a small amount (like most similar brushes do). Despite that, I am purchasing 3 more - two for gifts and a back up for me. This brush is fantastic.