My DD loved it last year at the MK. Just had the crown package (hair, nails, makeup) and took her own dress. You do need to book. Just booked by phone yesterday for October, you do need to give a cc number which they will charge $10 if you don't keep the appointment.
If you use photopass you can go to the studio in MK and have professional pictures taken and put on your photopass of your grandaughter all dressed up - even on the cheaper BBB packages.