The only ones we used were for Aladdin, and the rest were pretty much useless. They weren't needed, as those shows aren't crowded; and also there's no bad seats in the house.
If you do use Aladdin, they let you in first, in front of the rest of the people waiting. So you can pick great seats. They seem to expect you to sit in the orchestra section (right in front of the stage) but I've read here that you can go anyplace in the theatre for your seats. I would try to get them either in the back section of the floor area, right behind the railing, with the walkway that goes from side to side right in front of you; or on the first balcony, first row center. There's a couple of special effects that are much better seen from this vantage point-- one is right over head, and we had problems seeing much of it as we craned our necks back as far as we could. We were sitting 7th row center, normally considered prime seats, but second section or balcony would have been better!
Again, though, there's really no bad seats in the house.