The authors' vision of PLCs is certainly brilliant and could exist, theoretically, in every school. Unfortunately, true PLCs are something of a bird never seen in the wild, so to speak. It is nothing short of a tragedy that schools have failed, by and large, to enact the PLC structure that these authors' articulate.
Every educator in the US should read Chapter 9 - it convinced me that common assessments can actually lead to a more professional experience as a teacher, as opposed to limiting teacher autonomy. They provide the common text that enables educators to engage in meaningful discussion about best practices, review student data to ensure that all students are learning, and actually collaborate and learn from one another as opposed to existing confined to our individual classrooms.
This book both made me hopeful for the future of education and also infuriated that so many schools botch the PLC approach and water it down to a series of hoops for teachers to jump through. It truly is a loss for teachers and students alike.