It presents the "Keynesian" viewpoint on macroeconomics in an extraordinarily clear and interesting fashion. Frankly, I consider the introductory (read literally - first semester macro books) texts to be a waste of time. There is absolutely no reason this textbook should not be used for a first semester macroeconomics course (assuming one has already taken an introductory microeconomics course).
Suggested plan of study for those interested in a fairly serious study of macroeconomics (without an INSANE amount of mathematical preparation): this book and Barro's book with the same title. Barro's book presents the real business cycle theory approach in a clear manner (though the book is somewhat dull in comparison)...then decide for yourself which 'camp' is making the most sense.