As a student of Archaeology and Classical Studies, I am frequently hard-pressed to find accurate and intelligent variations and interpretations of ancient works by modern authors. McCullough's 'Song of Troy', while it admittedly takes several liberties with character personalities, follows the original 'Illiad' with startling accuracy of actions, but also gives insight as to different reasons WHY the characters may have taken these actions.
It must be remembered that the Illiad, while it will always be the authoritative voice, does not provide extensive insight into character development. For example, Achilles in the Iliad actually leaves the action quite early on and does not return until the later books near the end... McCullough has taken this and other events and tried to fill in the gaps, making the characters and their actions more human, and therefore better understood in the context of the original poem.
I can see how a purist might not appreciate this, but the reality is that there is no 'pure' version of the original either -- this was a poem that was handed down orally for generations before being written down, and for all we know we could have a substantially different version than was, say, being recited in Sparta or Pylos at the time. We know certain segments were altered for the audience, and it just so happens that someone somewhere finally decided to write their version down. Is it so wrong now, that a modern-day storyteller would tell the story again, altering it slightly for their audience? It doesn't break the purity of the original, it merely shows the continuation of this ancient tradition, following in the footsteps of Homer himself.
McCullough's 'Song of Troy' is entrancing and captivating, and will bring the famed story to life as you read. It will be a welcome addition to anyone's collection who understands that 'tampering' with a story such as this is not really tampering at all, but a continuation of a tradition unbroken through the ages -- "this is how things are, and Zeus himself, The thunder lord, could not make them otherwise." (Book 14, lines 50-51)