Not that insightful, right? You know these ideas quite well but just fail to execute them profitably, dont you? Now you may see why I dare not recommend it a "buy".
p.s. The best I can get is from Samuelson:- "You should take money seriously. In fact, you shouldnt enjoy investing. That's a trap. It makes you too active. You churn your own portfolio. You listen to stories, and most of the stories are not worth listening to."
Of the thinkers who were interviewed for this book, the most useful information comes from John Bogle, Gary Brinson, Richard Thaler, Joseph Lakonishok, and Jeremy Siegel. You can read any of several books by John Bogle that are more helpful than this book, such as Bogle on Mutual Funds or Common Sense about Mutual Funds. Jeremy Siegel's Stocks for the Long Run is a classic that anyone can learn from. The Lakonishok studies suggest lots of inefficiency in the markets that Brinson talks about. Thaler's work is cutting edge in helping people understand the systematic tendency for professional and amateur investors to make mistakes.
If you ignore the Markowitz, Samuelson, Bernstein, and Sharpe material in the book, you will have missed relatively little.
Modern financial practice has moved well beyond the original academic perspectives built around the theoretical assumption of a perfectly informed and rational market composed of identically-minded investors. Those useful research-based distinctions are not made here.
If you want to understand what you should be doing as an investor, I would suggest looking elsewhere. Depending on your goals and circumstances, different paths may make sense for you. If you are between 46 and 56, I suggest that you start with Charles Schwab's new book, You're 50 -- Now What?
Of the key lessons in the book, you should pay most attention to the advice to diversify, hold as much in common stocks as your risk profile allows you to do, stay invested all the time, keep costs down (taxes, fees, and trading charges), focus on indexes of sectors that have historically outperformed (such as small cap, value stocks), start investing as soon as you can, add to your investments as much as possible, and . . . leave well enough alone (forget about chasing the latest hot stock or manager to try to beat the averages -- past performance is not an indicator of what will come next).
If you do decide to read this book, check your behavior against the principles I have just listed above. Most people violate these concepts, and have missed the chance to make more money.
May you achieve all of your financial goals!