This book is written in a light tone matching the youtube videos that precede it. It encourages the reader to try out different design styles and character types and adopt a professional, structured manner of working on character designs.
Personally, I still felt it was too simplistic. I skimmed through it in half an hour, and I learned very little from it, although I may occasionally refer back to it when I practice drawing.
I was also uncomfortable with the uncritical discussion of the typical stereotypes à la 'a short, heavy man is good for character type X or Y', 'a typical heroine looks like this'. Yes, this image language exists, but I find those comics and graphic novels most interesting that do not subscribe to it or that at least subvert it in some way.
Overall, this book is aimed at teenagers with an interest in drawing super hero comics, rather than at more mature readers that appreciate graphic novels as art form.