One year we went on Dec 26th for a week. I had gotten such a great AP rate at the AKL concierge bunk bed room at $259 a night. That was back when your rate stayed the same the whole time.
We had been several times already, so weren't hell bent on doing every ride. We just wanted a nice vacation. The concierge staff was so excellent - they even had a cast member pick us up at the airport and drive us back (they had that service for concierge rooms that year). They booked all our dining reservations, even a NYE illuminations cruise on Breathless (I didn't even know what that was until we went on it - wow!).
We knew it would be crowded, so went to a park early then we'd leave when the crowds were too much. We really enjoyed the concierge lounge, the resort, and relaxing as well.
I was glad to have the lounge for breakfast and snacks (and many times the appetizers filled us up so much we didn't need dinner!). That really made a difference.
I definitely do not plan on going during that week again. But we had fun.
I also would NEVER recommend that week to someone who hasn't already been several times already. You would NOT see or do as much as another time of the year. The crowds are unbelievable. Really. The year we did it, each park closed to capacity almost every day. It got earlier and earlier as NYE approached.
I do love the week before Christmas, and we've done that as well as early December. Right before Christmas, I love the whole atmosphere. Last year we did it, stayed at the BWI (our favorite area) and had a nice time. If you want to be immersed in holiday music and decorations, you'll love it. I did. And definitely the Illuminations show is special.