Intelligent Design vs Biblical Literalism

Someone said "I believe in Intelligent Design as well as the Bible."

If you are a Biblical literalist, you have to believe in Creationism, not Intelligent Design.

If you are not, then what do you gain believing in Intelligent Design? The whole idea of ID is that a Designer has tinkered with molecules on occasion to get things moving, but that otherwise everything is as real scientists say it is.

So what this implies is that the Designer wasn't intelligent enough to get it right the first time, because if he or she had been, it would all just work and wouldn't require tinkering. So the Designer in Intelligent Design CANNOT be the All-Knowing, All-Powerful, One True God.

As a Christian, what then, do you gain by believing in that?