I was extremely leery of this book, as I'd heard the main thesis was 'To be an expert in something requires 10000 hours of practice'. No innate skill? Really? In the end I grabbed a copy from a charity shop.
His argument is actually far more subtle than that. Indeed, his requirements to become an outlier seem to be a) fantastic opportunities, grabbed with both hands b) enough natural talent c) relentless practice. He acknowledges IQ, and the fact that it seems to have a large genetic component, but suggests that it's more a hurdle where a sufficient level is required, rather than something where arbitrarily more is better. He gives the example of someone with a fantastically high IQ (way more than Einstein's) who, without the opportunities, has not really produced much. He also shows how, for top students, IQ does not correlated well with later success.
Indeed, there are quite a few strands running through the book, and he somehow manages to make the idea that the super-successful only got there with lucky breaks seem insightful! Other arguments are less obvious, and while not exactly scientific, his writing is very persuasive, even if I'm not sure it's right.
It's not a long book, but it's got plenty of ideas on the nature of exceptional success. It's very readable, and my initial skepticism has been converted into enthusiasm for a book that's much more nuanced than I expected.