If you haven't yet finished planning, you should definitely set aside time and budget for a few days at Aulani - it is a wonderful experience for the whole family! Especially if you are Disney-lovers.
Three years ago, we did Aulani for a big family gathering to celebrate our anniversary (I am a DVC member and have lots of family on the islands, so it was the best solution) plus a few days for quiet "couple time" on Maui. Everyone from the mainland and all the locals enjoyed the Aulani experience.
Besides all the usual stuff on Maui, I highly recommend taking the Maui Gold pineapple tour - you get to visit a working pineapple farm and factory (the only one still in Hawaii) and taste fresh cut, ripe pineapple (as much as you care to eat)! We also loved the Surfing Goat dairy farm - fun for kids to see all the goats wandering around and climbing over surfboards, and their treats were tasty (goat milk ice cream was delicious - who knew!). If you want to splurge on a meal, suggest enjoying a sunset dinner at Mama's Fish House - pricey, but wonderful food in a lovely secluded beach location.
Have a great time!!
Aloha