This is not a trivial, "new age", potboiler- it is a book of deep spirituality. Conway has succeeded in showing the proper, traditional interrelation of Goddess and God. Of course, she also points out the patriarchal distortion of the male and female roles in the mainstream Western religions, which no doubt explains the attacks she has drawn from both Fundamentalists and academics that reject the whole matriarchal/patriarchal approach to history. It should be noted that Joseph Campbell raised the same points about western distortion and imbalance in religion.
I cannot think of a better book for focusing on the natural balance of male-female energies in the universe. Conway shows that the true, original God was a complex deity, as opposed to the sterile, one-sided, authoritarian idol that was erected in his place. The original God is examined in all of his aspects: divine child, lover and consort, lord of creation, lord of the forest, hero and warrior, trickster, judge, lord of the waters, etc. The examination of his role as sacrificed savior (long before Christianity) is especially interesting. It is enlightening to find that the concept of double birth is symbolized in Dionysus. He who seeks and finds a true spiritual path is granted a second birth- or is "born again." These are not separate, distinct, non-overlapping aspects of different "gods", but are all aspects of the one. Indeed, it is shown that even in individual human beings, not only do we all contain these various aspects, but we also contain all the various aspects of God AND Goddess, for each person is fundamentally both male and female to some extent.
As for accusations of errors in the supplemental appendix', anyone can use a bad source now and then. Agrippa's three books are full of such errors, yet no one dismisses them. Just take a look at the excellent and extensive bibliography- Conway is a true scholar of understanding and depth.