No translation can be all things to all readers, so this version ought to be supplemented with other translations. As you note, the Dead Sea Scrolls were not widely available in 1966 and there has been other advances in scholarship since publication. For that reason, it makes sense to consult more recent translations, such as the English Standard Version, NET Bible, or even the New Jerusalem Bible.
On the other hand, the Jerusalem Bible sidesteps some of the problems made by previous English translations. It uses a full textual critical apparatus in the original languages that was developed for the 1956 La Bible de Jérusalem, a French predecessor. Earlier Catholic translations were from the Latin Vulgate. According to the Editor's Foreword:
The translator of the Bible into a vernacular may surely consider himself free to remove the purely linguistic archaisms of that vernacular, but here his freedom ends. He may not, for example, substitute his own modern images for the old ones: the theologian and the preacher may be encouraged to do this, but not the translator. Nor must he impose his own style on the originals: this would be to suppress the individuality of the several writers who responded, each in his own way, to the movement of the Spirit. Still less must it be supposed that there should be throughout a kind of hieratic language, a uniform ‘biblical’ English, dictated by a tradition however venerable. There is no doubt that in forfeiting this we lose something very precious, but one hopes that the gain outweighs the loss. It would be arrogant to claim that this present attempt to translate the Bible into ‘contemporary’ English cannot be improved upon, but at least (one believes) it is in this direction that translations will have to go if the Bible is not to lose its appeal for the mind of today.
Michael Marlowe notes:
Although it was prepared by Roman Catholics, the version does not serve to promote traditional Roman Catholic doctrine. The translation is little influenced by dogma (if at all), and even the annotations are of an ecumenical-scholarly character. This is a consequence of the fact that the scholars who produced both the French and the English versions were guided by the same principles of modern secular scholarship that many Protestant scholars have adopted in the more liberal theological schools. Traditional Roman Catholic exegesis is therefore largely absent from the Jerusalem Bible, just as traditional Protestant exegesis is absent from the Revised Standard Version.
He also notes that some of the scholarship presented in the book introductions reflect modern critical scholarship at the expense of conservative and (at times) secular viewpoints. Occasionally, the translation retains words that are deeply ingrained in Catholic liturgy despite better word choices being available. Reviewers have also criticized the way some passages in the Hebrew Bible have been translated; they did not adhere strictly to the Masoretic Text.
Conclusion
For regular reading and even as a text for casual study, the Jerusalem Bible seems perfectly adequate. For more detailed study, a student of the text would do well to consult more recent translations that reflect modern scholarship (including data from the Dead Sea Scrolls). The introductions, notes, and the text itself could be profitable for prompting questions about the Bible, but I wouldn't depend on them for answers.
