The reason I find it so interesting is it provides some hard scientific evidence for elements of the good life that most people will have in common. This kind of work moves what we should aim for as individuals and as a society out of the category of empty abstraction and into something purposeful and real - at least a little.
The book is interesting and provides a bit more rigor and links to primary research than other books. As you would expect, it's good on methodology, research methods and taxonomy. But it fills in the gaps rather than presenting something new, at least if you have read books like Seligman's Flourish: A Visionary New Understanding of Happiness and Well-being or the many other books on happiness.
There were some things that did strike me - this for instance:
And this outline of Martin Gardner's classification of very high accomplishment is interesting.
Gallup has learned that posing the simple question to workers: "Do you get to do what you do best every day?" provides powerful information... No more than 20% of workers in the United States believe that their jobs allow them on a regular basis to do and be their best. p195
Gardner proposed that there are four ways to be extraordinary; by being a master of some domain of accomplishment (eg Mozart and musical composition); by being a maker of an entirely new field (eg Freud and psychoanalysis); by being an introspector and exploring inner life (eg novelist James Joyce); and being an influencer (eg Gandhi and politics). Again we see the theme of pluraility of excellence. p215