We usually have 5 or 6 PS's for a week-long stay. We do a couple of character breakfasts, because we love them, and make a PS for lunch at Sci Fi (a must-do for every trip) then 2 or 3 others for lunch or dinner, either to try new places or maybe revisit a favorite. Other than character breakfasts, we have breakfast in the room, and the rest of our meals we eat counter service. This plan works well for us. We get to have a few special meals, but we don't feel tied to a bunch of PS's.
If we didn't go at really busy times of the year, we probably would make less PS's and play it by ear a little more.