No, you do not use ADR's for CS meals. Many people plan their CS based on the different foods available at each one--many venues are unique and people enjoy the tasty alternatives to hot dogs, burgers and chicken planks. In addition some enjoy "maxing out" the DP by choosing the CS that has the biggest portions, the most expensive items or the most food to share and stretch the credits.
I do a bit of preplanning as well, I know which places I enjoy certain foods at and plan to eat there when I am at a particular park. I find the variety very enjoyable and plan on CS things as common as a hotdog or exotic (for CS) as grilled salmon.