We were there this past Dec. during Pop Warner. They mainly stay at the values with overflow at moderates. If you are at a deluxe- you probably won't see them at all. We were at POFQ and saw a few groups on the buses and the food court- but didn't have any problems. If you are staying at a moderate- you might want to ask to be placed away from them. We saw very little effect at the parks- still very low crowds. We were thrilled! Now, we did see a few groups that were large and loud- the most annoying encounter was at Big Thunder Mountain- they kept chanting some 'cheer?' in Spanish over, and over, and over... So, after that, if we saw a large group we just went to another ride and then returned to our original choice. Friday at MGM was crowded- especially in the afternoon. They close MGM about an hour early that Friday for some special party for them at night. Other than that, we had no problems. Now, this is often a heated topic on here, so beware. Others have not had such good experiences. The worst I've read in the past were from people who stayed at value resorts- so you might want to avoid them at all costs!!! Other than that, you should be OK. That week was great! Great weather and the longest wait was 20 minutes without a fastpass on big thunder- most waits were 5-10 minutes! We even walked on Rock n Roller coaster and Tower of terror in the middle of the afternoon that Tuesday!!! So, our next trip will probably be this very same week - can't do the week before or after due to work. Have a magical time!!!! WDW in Dec. is so wonderful with all the Christmas stuff!!