I love WL and it's theming and having been there for Christmas 2009, I can tell you the abiance is incredible; I will return again for Christmas there when the opportunity presents itself again.
As for WCC, there are many mixed reviews of this restaurant but I personally enjoy it and go there every time we are back in WDW. I enjoy the endless skillet myself; it is an excellent value for the price and I have found it to be very good. As for which meal? I am not a big breakfast eater so I usually just get a bagle and juice. If you are on the
DDP I think you get much more bang for your buck using it for dinners instead of breakfast and lunch. However, there are some who like to use some of the dining credits on character breakfasts if they have kids.
Enjoy the WL for Christmas, you will love it