The most disappointing chapter was the one on the intelligence failures leading to 911 -- as it seems to blame 911 on the shortage of Arab speaking CIA informants and field agents within Muslim terrorist circles. This directly contradicts good evidence accumulated by 911 researchers that the terrorists allegedly responsible for the hijackings had prior ties with the CIA, either directly or indirectly via Pakistan's ISI. This first came to light with the millions of dollars of short selling of millions of airlines shares on September 10, 2001 (short sellers only make a profit if the value of a stock drops -- see http://articles.sfgate.com/2001-09-22/business/17618762_1_ual-stocks-short-sale) and subsequent complaints from embassy officials that US intelligence ordered them to issue American visas to 15 of 19 of the hijackers. http://www.davidicke.com/articles/war-and-terror-mainmenu-45/31549-cia-ordered-visas-for-15-of-the-19-911-hijackers-in-jeddah
Hersh's section on Adnan Khashoggi was an even bigger letdown. According to Hersh, Khashoggi set up secret meetings between a Saudi envoy and Richard Perl to negotiate a secret US-Iraq agreement for Saddam Hussein to go into exile. The author mentions Khashoggi's links to the Iran Contra scandal and the infamous CIA bank BCCI. However given that this is a book about 9/11, his failure to mention that Khashoggi was linked to the short selling -- or that he was part owner of the Florida flight school where three of the hijackers trained -- is a glaring omission. See http://webfairy.org/constantine/index.htm
(Note: You can view every article as one long page if you sign up as an Advocate Member, or higher).