We're not in a hurry but don't want to reserve a week and be bored after 3 days.
Were now on our 20th year of spending at least a week or two there, every summer. We aren't bored yet. That said, there have been members here who whined that they were passing through the Hills on a cross country trip, and stopped at Rushmore, but quickly moved on, since "there was nothing to see". I don't know it they expected the second coming to begin, a live action Godzilla movie, or what? But, most folks can spend a few weeks in the area, and have a great time.