I agree with Eliezer here, but Robin also has a point. I think we should distinguish between the transition away from one position and the transition towards another. Because falsification is relatively easier than confirmation, once the right evidence falls into place, a rationalist should expect to quickly abandon prior beliefs. The problem arises if something else quickly fills the void without being thoroughly tested. I saw a couple high school friends fall into the trap of thinking the opposite of stupidity is intelligence after leaving religion behind.

Beware a slow transition away from old beliefs as much as a sharp transition to new ones.