For a starter, this is not a book about problem-solving, it is about decision-making, or rather the material you may need to have before taking a decision.

If you try to solve a real problem (especially wicked ones) and utilize these techniques, you'll be none the wiser. If don't know if this is really "the" McKinsey method (could be, as they seldom try to solve problems) or a unique Australian approach to Management (I have recently read a number of books from Australia that has got me questioning the management culture down under, but I may have been unlucky…)

Nothing new under the sun in this book, and they even fail their own first point in their examples (define the problem).

Not recommended reading.