Well, that depends on what time of year you are talking about. Some nights its standing room only and if you want a seat you need to get there 2 hours before the show. That would be peak season. Then yes, I'd do the package.
I've done the package many times for fear of waiting in a line. It turns out, I had nothing to fear. I've done the package August, Sept, Oct, Nov and Dec....all off season. I finally tried doing it without the package twice now (August and Oct) and realized there is no line. I entered at one hour before and had the best seats ever and I got to eat where I wanted to; Sci-Fi and 50's Prime time.
With the package, you are only guaranteed a seat up to 30 minutes before; then they release the seats to the general public IF they are needed (standing room only). The seats are to the far right. The waitress will tell you to enter between 45 minutes and 30 minutes before.
So, IMHO, if you are going off season, then I wouldn't do the package and I'd get a seat about one hour to 45 minutes before the show and enjoy my meal where ever I wanted to.
If you are going peak season, then I'd do the package and still get there 45 minutes before the show.
No matter what you decide, seats are still 'first come, first served'.