Even though it has been 50 years from the time these discoveries started to be published, this is the first time a Hebrew/English edition of the "published texts" has ever appeared. There have always been English translations available, regularly updated as the findings were gradually released, but students who wished to explore the original language always had to visit some college library and make copies from the journals or consult some edition that was in French or German. Individual scrolls or a particular grouping of text might appear in both languages, but nothing presented this corpus to English readers before this Study Edition.
The work itself is not a critical edition. It is actually more of a catalogue of the corpus of manuscripts, providing the non-Biblical texts in their original language (Hebrew or Aramaic) with an English translation on facing pages. As a result, many of the texts occur several times, because every manuscript of each work is provided. This reveals how some of the texts were recovered, as one set of fragments fills the gaps of another. But in each case, the "recovered" text is given in brackets, and the student is able to flip back and forth to see how the fragments are related. However, there are many reconstructions that are not supported by an actual manuscript, so this edition does make it possible to detect unsupported emendations, which is of the greatest importance to any student.
As for the subject of Qumran itself, the site, the caves, the dates of these materials, the place they hold in ancient literature and history, even their relation to the Bible, there is not a word. This is purely the sources without comment, and leaves you to still obtain a good edition of the non-Biblical materials we have always had (Enoch, Jubilees, Testament of the 12 Patriarchs, etc.)which are only represented by fragments in this collection, but essential to understand this corpus. Even worse then this, the Biblical book of Ecclesiasticus (Ben Syrah), also represented by fragments in the Dead Sea Scrolls, does not exist in such a convenient Hebrew/English edition.
While I find this work satisfying and useful, it has occurred to me that, after all these years, even if this edition was worth the wait, we must still wait for such materials as I listed above to be presented in a similar form.