We have stayed at both CS and POR. Between the two I think that I liked POR better. Probably because each night that we got back from the parks we took the boat ride to the Marketplace. It was very relaxing. We stayed in the mansions and they were beautiful! I didn't like the Aligator Bayou section. I am not a woodsy person so it just didn't appeal to me. The theme pool is great, although, we used the quiet pool more because it was closer. Boatwrights breakfast was awesome each morning. Try the french toast if you stay there.
CS is also a great resort. We really liked everything about it. The theme pool is awesome. The Peppermarket had some good food. The bar area was nice to sit and have some salsa and nachos and margarita's after the parks. The bus service was great. The wait times weren't long, and as the pp said it never feels like it takes that long to get anywhere from there.
I have never stayed at any of the Pop's so I cannot attest to what they are like.
We went this past December, actually our travel dates were 11/29-12/05 and I thought that it was busier than Decembers past. The weather was cold and we only got to swim one day. I don't go to Florida to wear jeans, jacket, and sweatshirt all at the same time. If I want to do that I will just stay home. The christmas decorations were beautiful, but I think that we are going to plan on going in the fall when it's a little warmer. I don't know how much Pop Warner really affects the parks during the day because that is when they are off doing their games and such from what I understand.
Good luck making your decisions. It's a tough one, but once you make it go with it and have fun planning the rest of your trip!