I'd have to say HDDR for sure. You don't have to worry about weather unlike Mickey's BBQ. A 7 yo girl might appreciate the luau, but she would also like the HDDR. Don't forget Cosmic Ray's. Sonny is the cheapest dinner show on property, IMHO.
My brother took his children to Ohana and they liked the luau, but I think HDDR would be more up my 7 year old's alley! I haven't been to it, but everyone I have talked to had nothing but positive comments.