I disagree. I don't think you need the Fantasmic package for the time of year you are going.
I would eat where ever I wanted to, which would probably be 50's Prime Time, and then I'd go get a seat for the show either 1 hour or 45 minutes before the show and get great seats in the center, half way back.
With the package, you will still need to enter between 45 minutes and 30 minutes before the show and the seats will be to the far right. They are no longer guaranteed at 30 minutes before.
I did the package several times off season and it wasn't really needed; one time (with the package) we actually walked past the package section and went and got seats in the middle. We did it twice without the package and had the best seats ever; in the center, half way back.
Good luck deciding.