Let me begin by saying that I would recommend this book. The exercises in most of the sections (particularly 'Who am I?', 'How satisfied am I?', 'What changes do I want?') were very helpful in helping me to identify what is important to me in life, what I feel is currently missing from my job (as well as, to some extent, my personal life). The book is written in a very motivational style and the exercises never feel like 'hard work' but make self-analysis and reflection very painless and even enjoyable.
I would recommend the book to anybody who wants to make a change, feels 'somehow' unhappy but can't quite work out why or what to do about it, or anyone who feels reasonably content but worries they might be missing out on something.
However. The book is now in its fourth edition, the last one having been published in 2009. Unfortunately, some parts of the book are now incredibly out of date. The book was first published in 1984 and most of the authors' research, statistics and, unfortunately, attitudes stem from the 1970s. I would suggest the publisher encourage the authors to make much more thorough updates to the next edition to bring the text in line with the 21st century. Section 2, 'Where am I now?' is particularly poor in this regard. This section discusses the life cycle e.g. how you might define success in your early 20s compared to your 50s etc. Unfortunately it contains a number of unforgivable references with regards to women. Reading this section, one would have thought 'career women' were women in their 40s working part-time as a secretary after decades spent at home as a wife and mother. In particular, the suggestion that 'The woman not married by age 29 used to - and maybe still does - feel embarrassed by it' (p. 73) made me howl with laughter! (Particularly since I am 31 and, needless to say, it has never occurred to me that marriage is something I should be thinking about.)
In addition, the information given with regards to career patterns (surely all careers are 'cyclical' now?), 'dual career families' and the employment market are also very dated now. For example, page 31 on 'Life and Career Management in the 1990s' includes the following sentence: '... in the foreseeable future, young people will be in high demand as there are fewer of you.' Not exactly in line with current prospects for youth/graduate employment!
So, overall, the book is embarrassingly out of date. However, the exercises to identify what is important to you and how you want to spend your life are still very valuable and I would recommend the book based on these. Just beware that the book also contains some 'time travel' back to life and attitudes of the 1970s. (The 'job families' identified in the appendix are also on the traditional side.) This is a great shame because a fully revised and updated edition would have a great deal to offer.