I am voting no. We have had them (nothing else that we wanted, so took one near the show time that we were going to), and we have not had them. Unless you are very particular about your seat, it isn't generally needed. Christmas week - maybe.
Something else to mention - we had fast passes on our last trip and it was raining, so they combined the lines (fewer cast members needed). So the fast pass did nothing. They made everyone from the fast pass line walk over to the stand by line and get behind those people.