Three significant mistakes suggest that the authors are not insiders of a community that is certainly out of step with modernity and imo with Jewish culture.
Page 173: a picture of Rav Shach is captioned as Rav Elyashiv.
Page 198: claims that the Chabad HQ is 777 Eastern Parkway when it is famously 770.
204: In a story about an unusual Rabbi, they leave out the name of the Rabbi, famously Shlomo Zalman Aurbach, who's son, Shmuel Aurbach could very well have been the subject of the book. The Rabbi was not unusual but considered by many to be a Gadol HaDor of his generation, and thus representative of a significant amount of the population, not "unusual".
On the content of the book, these problems appear frequently in both their characterization of the Haredi world, of the State of Israel and of democracy.
The book often conflates western democracy with democracy, a typical err of the west. I.e. the Haredim have used their political power to limit over reach of western norms of egalitarianism to impose structures that are inauthentic to Semitic society. (Women judges on the religious court, for example)
Beyond this, the book assumes the definitions of a state for the Jews and a Jewish state. The former, a western output of democracy that Jews and others can live, whereas a Jewish state is incorrectly defined as a theocracy based on Haredi guidelines. The state of Israel should define their mission statement in a way that clearly defined what a Jewish state means and hopefully in a way that Palestinians, secular Jews and Haredim see themselves in that mission.
The book also makes the case for a constitution and the failure of the Zionists to write one speaks to the failure of the Zionists to determine the next stage of Jewish history with the vehicle of the state of Israel.
Lastly, the book is not sensitive towards Palestinian aspirations and towards the end suggests that a two state solution is the only way to get rid of a hostile neighbor.