This is an excellent resource for those who are prepared to move beyond the limits of the Strong's Concordance. If you are ready to ramp up your understanding of the original language of the New Testament this is a very good place to start.
Not knowing Greek myself, this would have been next to useless to me without an exhaustive concordance, which I ordered along with it. I really like how explanatory this thing is!
A lot of the entries have multiple paragraphs worth of text packed with information on a single word. For at least some verbs, it shows how the various tenses (future, imperfect, aorist, etc...) of individual words appear in Greek. Part of the appendix has more verb forms, but they are not numbered. Another part of the appendix lists words, unnumbered, unique to individual New Testament writers. This lexicon has some things which I am not sure I will ever use, such as references to and quotations from ancient, non-biblical authors.
My only complaint is that I find it hard to follow along with many of the abbreviations. Some of the abbreviations are not explained in the Explanations and Abbreviations section, which I guess is because they are not unique to just this book. I can get used to it.
Thayer's is NOT a good tool or a "classic". It was a fairly decent tool in 1889, which is the edition sold here. It has been terribly out of date for a century, since it was written before most of the papyri and inscriptions were discovered. Do not accept the myth that "old" is somehow from the golden age of erudition or from a more sanctified era.
Not only is Thayer incomplete, it is positively misleading, since he makes claims (for example, about the words "agape" and "phile") that are now discredited...although still popularly employed in books and sermons. There is no substitute for the up-to-date work of the 3rd edition of Baur's Greek-English Lexicon of the New Testament and other Early Christian Literature (2000). For people who do not know Greek, even Vine's is better. It's classic in the sense that a manual on computer software from the 1960's might be viewed as a classic. Its only benefit is that it is coded to Strong's for people who do not know Greek. Please, if you do not know Greek, don't teach as if you know the Greek!
I have to question CBD's ethics in saying "For over a century, Thayer's has been lauded as one of the best New Testament lexicons available for any student of New Testament Greek." This is not truth in labeling. No serious New Testament professor has recommended it for the better part of a century.