Daryl I think it depends on your expectations. The parks will be packed but the hours should be extended, and the Christmas decorations are fantastic. If you want to go to try to ride all the rides in as little time as is possible, that week is not the time to go.
If you have small children take into consideration what it is like to try to herd and guide them through huge throngs of people. Consider how patient your children (and everyone else in your party) are to wait for lines for everything including food, transportation, etc.
If I were going that week, I'd be using EMH and get there plenty early to do the best I could to ride the big stuff before the parks get crowded. BTW, the week or two before Christmas is an excellent time to go.