How strange it is, that I, a student and professor of the Greek New Testament, would object to the electronic publication of a classic Greek-English dictionary! Yet object I must.
Baur and LSJ are top-of-the-line lexicons. They draw from discoveries that have been made of hitherto lost books from antiquity, and especially of the papyri and inscriptions. Besides which, digital databases such as Thesaurus Linguae Graecae (or TLG; ancient books) and the Packard Humanities Index (PHI; papyri and inscriptions) now put within the reach of all interested students the ability to search through almost all known ancient material within minutes. We might reason – if two lexicons are good, then wouldn't three be better? The answer is a firm no. For example, Thayer states that the word agapē was invented by the inspired translators of the Septuagint in the 3rd. cent. BC, and that pagan Greeks had not previously known of the word. Using advanced software I was able within an hour to disprove Thayer in great detail, demonstrating that agapē was known and used in pagan Greek – although not frequently – long before the translation of the Septuagint and after its publication, yet in works that show now Jewish or Christian influence.
Was Thayer mistaken? No he was not...given the data that were available when he wrote. But new data have come to light since then, invalidating their statements.
Some people have the idea that Thayer, being a classic, will provide a fresh and perhaps more spiritual perspective. This is not the case. The person who reads Thayer cannot simply weigh his opinion against Baur’s and decide which he or she prefers. LSJ and Baur, whose conclusions are not fallible and are sometimes debated, will always have a decisive edge over an older lexicon simply by having publication dates of 1997 and 2000 respectively.
We must use the very best tools that are available, and we must be prepared to pay the appropriate cost in order to make use of recent research, even the $150 for Baur. Or, we must commit ourselves to seek out the best tools where we can find them – in a library, or using Liddell, Scott and Jones gratis from the Perseus website! (www.perseus.tufts.edu). I’m sorry to conclude that, by publishing Thayer, Logos – of which I am a devoted fan – is part of the problem.

See also my post: “What books have I used to write a commentary on 1-2 Thessalonians?”