The advice and research in this book applies to very large corporations, with very specific investment returns over a period of time. Very little advice could be applied to small businesses (maybe the Hedgehog concept). Sure their research is impressive, but even the author admits most of this could not be consciously recreated. One of his "great" companies was Circuit City and they closed up just a few years after writing this book. All their choices of "great" companies were made based on stock market returns and they were very clear about this...for those who don't understand what this means; the author based his research of "great" companies on the results of a speculative market (the company is valued by investors/speculators!). Not a good judgement of a company being good or great, but it was hard data so they took the easy way.
This book just ended up being a narrowly defined research project by academics that have probably never had more responsibility than thinking they are the smartest person in the room. This is in no way a managerial development book as it is often thought as, or recommended as. It was a complete waste of time, unless of course you are intrigued by these company's histories. But they are smart enough to get professors and executives to recommend it everywhere. I'll give them that.