The other deciding factor was, interestingly, watching clips from the shows I was trying to decide from, on youtube, getting a better feel for how the girls would like it.
Here's one of the clips that helped me decide on The Lion King:
I did not show the girls the online clips, because I wanted them to be totally surprised. This paid off - their eyes were as big as saucers as they watched this opening live and in person, and they were captivated for the rest of the show.
Hands down the most creative, fun, enjoyable musical I've seen! If you ever have a chance to go for yourself, my review is - "Totally worth it!"