I agree with BCV23 about the show itself.
Whether you do the dinner package or not, you will likely have to stand in a line. The difference is that the dinner package guests (line to the left) are assured a good seat, while the general admission folks (line to the right) are not assured a seat at all. The seating is about half and half (or was a couple years ago), but the show is very popular so you need to get in line early for general admission.
Making CP dinner package reservations is a safe choice. Depending on the restaurant you choose, the make-up of your party, and your dining habits, you may pay a hefty premium for your guaranteed seats.
A party of adults with expensive dining habits may actually save money on the package. But a family with children over age 10 may pay $10-$20 more per person than they would ordinarily have paid at that same restaurant.