I'm not sure that you should've conceded that bit about discussing the people so quickly, cnorman.
is not convincing to me. Religions necessarily make their presence felt in the world by the actions of their believers. Therefore, even though Islam and Christianity have similarly barbaric commandments about what ought to be done about various types of crime/abominations/etc, the fact that they are practiced in the Islamic world (Saudi Arabia, cutting off hands of thieves, the near-universal discrimination against women, etc), makes Islam the more barbaric religion of the two, independent of the fact that there may or may not be more barbarity in the Qur'an than in the Bible.
Now, if we're talking about the religions on a purely literary sense, and basing our judgments independent of religious impact on the real world, you'd also have to withdraw your somewhat distasteful "Dictators" argument. Take your pick.