We did our first Disney Christmas last year - we arrived on Christmas Day and came home Jan 3rd. I'd read on here that MK was the place to be but decided against it for many reasons, including -
1) Mk always closes first due to capacity.
2) MK is more compact and so handles the crowds worse.
We decided to hit EPCOT for NYE as the park has a greater area for guests to spread out over - even when the park is shut due to capacity. Plus, we prefer Illuminations to Wishes AND we watched all the MK NYE celebrations / fireworks on Dec 30th !!!