The major difference put simply is that the translations contained in King James are considered to be not as accurate to the original text because it was translated by Englishmen without a total knowledge of depth of the Hebrew or Greek languages. This is mostly a "fluff" argument though. The real meat and potatoes of the difference is that "New English Versions" or so-called "Catholic" bibles contain additional books which protestants and others considered a hack-job or gnostic.
These books are: Tobit, Judith, Wisdom, Sirach, Baruch, and I & II and Maccabees.
