I was not at all familiar with the ideas of Jung before reading this compendium of his work, so it is difficult for me to pass judgment on the comprehensiveness and impartiality of the book. However, seeing as it was praised by leading Jung authorities, and that Storr has structured the volume in such a way that it is left to Jung himself to expound Jungian philosophy, it is a safe guess that we are presented with the undiluted thought of the founder of analytical psychology.
The book is split into ten chapters. Each one deals with a specific aspect of Jung's psychology by using excerpts of varying length. Storr introduces each excerpt with a concise summary of its content, which is especially helpful with some of the more esoteric passages, of which there are a few!
This is a fascinating read and just brimming with edifying stuff. Jung's defence of religion is refreshing and original; his interpretation of the story of Job is just excellent; his exposition of the archetypes, although rarefied and sometimes obscure, is exciting and stimulating for the imagination.
Familiarity with his unconventional mode of thought will leave you more open to the possibilities inherent in man and will introduce you to 'wacky' ideas made plausible. Much of the material in here has a (briefly) liberating effect.
Storr's introduction at the beginning of the work is invaluable, and I would recommend it be read before and after tackling the main body of the work.
If you are at all curious about Jung but don't know where to start, start here.