Our experience is from '04, we were at BWV from December 19th through the 23rd, and each day there were lots more people! However, from BWV you could see the practice special fireworks planned for New Years Eve, (maybe Christmas) and just the practice runs were special, so we would have loved to stay longer!
We have never been in a high crowds time, so I can't compare, but we did everything we wanted to do during that time...including a "wait in line" Candlelight Processional. We did mini-golf over by Blizzard Beach one night, that wasn't terribly crowded at all. We did the cute Winter one.
That was the year of the "before Christmas" monster snow in Dayton! What a mess going home that December 23rd!
Bobbi