This book is based on the older single manuscript Ben Chayyim Text that was used prior to the development of the BHL and then the BHS manuscript. This volume lacks many of the words that are found in the Aleppo Codex and the Leningrad Codex. It is not always useful for anyone working in the modern manuscript of the "BHS"; between 80-90% the words will be there. KJV only people will find this volume useful everytime since it based on the Ben Chayyim text that is behind KJV and it will contain every word found in it. It should also be noted that it will not correspond to a Jewish understanding and translation of the text in many theologically significant text and other text as well; the Jewish text is based solely on Aleppo Codex. I hope that somewhere out there soon someone will produce an updated version. If you do not have an understanding of Hebrew and you are using the BHS you will need a basic understanding of Hebrew to figure out the meaning of words 10-20% of the time.
This is an excellent lexicon for those who know little more than the Hebrew alef-bet (alphabet). You can look up any word from the Old Testament exactly as it appears in the original text and the lexicon will do all the parsing for you! It's true that this can become a crutch for those trying to learn Biblical Hebrew and expand their vocabulary, but in the beginning it is much easier to use than the "BDB" and it keeps you away from getting addicted to using Strong's numbers all the time (a very bad habit that is hard to break).
The reason I give this book 4 stars isn't because of the content, but the quality of the printed book itself. The pages are very tightly bound, so one must hold the book open in order to read (not convenient when you are thumbing through various lexicons and concordances at the same time). Also the verse references at the bottom of the page are very tiny and can be hard to read. Nevertheless, I'm greatful that Hendrickson would print such a great work at such an affordable price.
This lexicon is useful because it lists the words in the Hebrew Bible alphabetically, regardless of the lexical root, and then gives you the root and the form of the word. It must be used judiciously though. Over reliance on it could prevent your gaining a deeper knowledge of how the language works. So, it has its place as a useful tool alongside such works as Brown-Driver-Briggs, especially if you are doing the bulk of your study on your own without the help of a teacher.