Hi Andrea,
Thanks so much for visiting the Disney Parks Moms Panel with your question!
My husband and I have eaten at
California Grill many times over the years. It is positively delicious, and we love it. It is also reopening soon after some enhancements, so we cannot wait to eat there again. Notice; however, that I said my husband and I have eaten there. Our daughter is 8 years old, and she is only now just getting to an age where I think that she could truly appreciate a meal at California Grill. A meal there can be many courses, which is how we like to enjoy it. Children are more than welcome at California Grill, and we have seen many there in our times there; however, for us, we have chosen to keep this as an adult restaurant. If your 4 and 7-year old are accustomed to slightly fancier and more elegant restaurants, they may truly enjoy a meal at California Grill.
When my daughter was at the age your children are, if I were faced with this decision, I would have stayed at Disney's Hollywood Studios and seen
Fantasmic! It is a truly wonderful and dazzling spectacle. My guess is that years from now, your girls would remember seeing Fantasmic!, but maybe not an evening at the California Grill.
I hope that these thoughts help with your decision, Andrea. Have a great time planning your Walt Disney World vacation, and please do not hesitate to ask if you have any further questions.