We were there two years ago in the evening/night during Xmas week. Very crowded but the atmosphere was very festive. Not only were there decorations and lights, etc., but they had quite a few performers entertaining the crowds. My children are teenagers and can handle the press of people. If you have little ones, maybe getting to DTD early in the day is a wiser option. Can't say if it's worth it since that is dependent on your personal taste.
We found the Santa lines shorter at Epcot and MK. The decorations are festive. Less people on a weekday morning or afternoon. If you are driving, the parking garage opens Nov 20th.