I even wrote my undergraduate honors thesis refuting his conclusion about a "Fall". Socially and economically one can trace a gradual shift in power and influence from the secular aristocracy to the religious aristocracy in the Imperial urban centers in the west and the east - Rome, Alexandria, Antioch, Constantinople. Transformation is a better word choice than Fall in the Western half anyway. At least till the 6th century when Justinian's reconquest destroyed Italy. It wasn't the Germans who led to the "Fall". It was the Greek speaking Romans of the East. And alas their demographic decline began with a serious plague in the 6th century that then allowd for the Arab conquests of the 7th century.

There are currently many avenues where one can dispute Gibbon. And the idea that Christianity somehow led to the downfall of "Rome" is currently a crazy idea.