We visited twice just this year. Definitely get an AP - it will save you on the resorts (discount on rooms) and food. With the AP, you can purchase the Disney Dining Experience card ($65?) and save 20% off on food/beverages, spa, boat rental, shopping at certain stores, etc.
Is the family joining you on both trips? If not, just you can buy the AP for yourself, and get all the discount benefits. Then, just buy the regular passes for them around x-mas.