Another way to put it might be that they are more secure in what they wish to see from a policy standpoint, and the personality-based sideshow of a campaign is usually irrelevant to that. Assuming of course that any given candidate is upfront about their platform and sticks to it.
IE: That more informed voters are a subset of the population of early deciding voters.
The counterpoint would be informed voters who make late decisions, not low-information voters who decide early.