I'm far from being an expert on either AA or AVRT, but I can take a crack at expressing my own understanding, limited though it may be.
I agree that if you distill the concepts of AVRT and Higher Power to their essence, it turns out they accomplish much the same thing, except the approaches come from different perspectives.
First of all, according to my understanding of AVRT, it does not promote belief in the Addictive Voice (or "The Beast," as it's sometimes called) as actually being an external entity. It's just a convenient way of distinguishing thoughts that originate from one's addiction (one's "lizard brain") from thoughts that originate from the higher self.
Similarly, AA's Higher Power isn't necessarily an external entity either. The Big Book itself refers to "an unsuspected inner resource." Most people simply find the construct of the traditional Western "God" (as it's put in most of the book) to be what they're most comfortable with.
In both cases, the point is to move beyond the old patterns of thinking and behavior that always led back to drinking. As it's often said, it's tough to solve your problems using the same brain that created them. Both the Higher Power and AVRT concepts offer workarounds which are sometimes visualized as external entities, even though they need not be external in order for the concepts to work.
In both cases, the result is the removal of the problem.
Whether an individual identifies better with one approach or the other isn't necessarily inherently "positive" or "negative." It's just what appeals to that person's personality thanks to their particular blend of nature and nurture.
I don't feel like I got all of this particular pitch, but it's the best I can do at the moment.