The Discontented Little Baby Book…thoughts?

I’m a mom of two. I have a 2.5 year old and a 9 week old.

I started reading this book after having my second. Lots of things make sense but also goes against so many things I’ve been conditioned to think about, especially when it comes to baby sleep.

Just curious to hear others thoughts on it. Was anything helpful for you? Did you completely change anything you were doing after reading and saw improvements?