I can see your dilemma. They are both great restaurants. My DH and I have dined at both multiple times. They both are excellent. If we had a choice, we would choose Narcoosee's. The restaurant is located overlooking the lagoon and the view of the Wishes Fireworks (music is piped in and the restaurant goes dark) from your table, or out on the deck, is priceless. After the fireworks you can then see the Water Pageant Parade out on the lagoon. We have gone to Narcoossee's with and without our children. They are DS13 and DD10 now, but went with us when they were 5 and 7.
We make 5:30 ADR's, go a little early and request a table by the window. It has worked every time. We will be there on Dec. 3rd...I can't wait.
Enjoy what ever you decide, they both are great.