I think its very hard to read classics let alone write reviews about them. First of all if you have not read a book that is there for decades - you missed big time (unless you are from the young breed reading books one by one :P). Secondly, you would have heard from friends, lectures and other books to the extend that you may think the book content is repetitive!
Having said that and taken a bail :) my honest opinion after reading the book was that it had no 'aha-aha' moment. All it says is that change is inevitable and learn to move on!
The beauty of the book I believe is how Dr. Spenser has put forth his thoughts. The book could be read in half an hour; however the content resonates once you start to reflect yourself. The book essentially talks about the fact that we should not get lazy and fall into a comfort zone once we find some success. As per the book success is not everlasting; we have to change according to the circumstances; there is no point in thinking an 'auto-switch' for recovery will be enacted!
A quick read especially when your are emotionally down that will help you to rejuvenate and move on. I really liked the simplicity with which he has written the book!. A good summary is available in wikipedia with the key take-aways.
When I read the book, some of the thoughts I read in S.U.M.O (Shut Up, Move On)by Paul McGee resonated well :)