Daisylove,
My family (me, DH, 3DS (8,3, and 8 mos) went December 27, 2002-Jan 1, 2003, it was a nightmare. While it was beautiful with the decorations, the lines were enormous and the crowds were huge. It was to cold to swim and I could not make any PS for good times (off times only available ie later in the evening) not good with three little ones.
Also the airports were packed and the fares were very expensive.
IMO I would not do it again, we know go in Oct or early Nov.
My friend went the first week of Dec. right after Thanksgiving 2003 and loved it. The decorations were up and the crowds were light.
The only bright spot was that we bought DVC for a Christmas present to eachother.