Another advantage to the plan is that you can get special seating for some of the shows (like Beauty and the Beast, Playhouse Disney, Tarzan Live, etc.). One of the disadvantages is that you have to call beforehand. A CM informed me that priority seating can be made as late as the day of the showing, but the liklihood goes down. Apparently the seating is for the first two or three rows. Otherwise, you need to stand in line on the first come, first serve basis.
It's still going to be worth it to me because I know my children already have their "souvenir money" and I don't have to worry if I set enough aside since it's already paid for. As far as a princess breakfast, make sure to call as soon as it becomes available (90 days prior to the seating). Otherwise, you may have to settle for a different character breakfast. I had to change the dates of my vacation so I had to give up my princess breakfast. There haven't been any cancellations for me to get in, but I'm sure my kids will love Chef Mickey's. Besides, we're just doing Cinderella's Royal Table for dinner instead or breakfast now.