I think resort restaurants (mostly deluxe) are even harder to get because you're right there where you're staying and if you don't feel like going out (raining, too hot), you just go down to your restaurant and eat. Depending on the time of your meal, it can be tough! To some people, these restaurants are a destination unto themselves (1900 parkfare, whispering canyon, chef mickeys, cape may cafe, to name a few). You can do walk ups but just be prepared to wait, which, in the WL, is not an unpleasant wait! I think it's better to be prepared and have ADRs; you can always change your mind but at least you have a plan! Good Luck!