I agree with the other posters that your girls won't feel out of place if they aren't in costume. However, my Dd4 dressed like Aurora when we went to PSB breakfast and when Aurora came around she made such a big deal about it. She stayed at our table talking to Dd longer than any of the other princesses and Dd was so excited to get such attention from her favorite princess. Also, all the cast members we saw on the way over from the resort (bus driver, cm at ticket gate) commented on it. A few called her "Aurora" and one said "your majesty"- it was really cute. So, you will have a great time either way, but dressing up could add a little bit of pixie dust if your girls are into it.