Quantum class ships handle reservations a lot better than Oasis class and you should be able to make dinner reservations for the whole week. That has been our experience on multiple ships of this class.
As far as the food, some like it, some don't. We find the food always is hot and fresh in CK. My DH loves the french onion soup in CK and gets it every night. I find there are more fish options in CK.. You should be able to find the menus in the app to get an idea of what they have.