We went last December, the 6-11 and it was PERFECT. The weekdays were slow, chill, and easy going until evening times (after 5 pm). The only times it felt CROWDED beyond belief were during the castle lightings and snow on Main St. Then, it was quite difficult to maneuver the strollers, but still totally worth it. Saturday was our last day, and was certainly busier, but still not crazy. We went in July last year as well, and December was NOTHING compared to July. You couldn't pay me enough to go back in July. In contrast, we're planning on heading back this December. It was fabulous, the weather was in the low 70's all week, and a lightweight sweater was almost too warm during the day. A fleece jacket was perfect at night, other than one night where we broke out the hats and gloves. I highly recommend going in December, the decorations, and songs, and things make it impossible NOT to be in the Christmas spirit! I'm sure it gets busier the closer you get to Christmas but we had a GREAT experience this year! We rarely waited more than 10 minutes for anything, except Toy Story Midway Mania, which we hit up about an hour after CA opened, and waited 20 minutes for. We walked onto most things, and were able to see everything we wanted with no trouble!