I would say it depends on when you go. Mid summer, the later show is fantastic because you can see the fire dance in the dark. During the summer, that same fire dance loses some “spark” in the sunlight. Plus, no a/c and that theater is RIDICULOUSLY hot in the summer. The further back you are in the theater, the hotter it gets.
So, if you are going in the summer, the later show it is! But, any other time, makes no difference.
Good luck, we love that show and we love the Poly. We ponied up one time for the first tier seats and ended up with the front and center table. They put me in the show a couple of times, my daughter a couple of times, my wife once, and we had a blast!
Good luck! Have fun!