The system would not allow me to make fast pass+ ressies for the dates we would be at Disney; the system had different dates blocked for us ... strange. The CM gave us an "open" fast pass+ for one park each day (3 FP+ for each day). She said we do not have to choose the attraction ahead of time; we can just walk up and use our fast pass whenever we want to. ?Has anyone had any experience with this? I don't want to get there and find out that I should have made choices ahead of time.