My children are 3 and 6, so the port adventures were a challenge for us (many of them didn't allow my 3 year old, and others filled up before we could book them). My son really enjoyed Best of Hilo. My husband and I found it rather dull, but they brought us to the nut plant, where you could sample treats and watch the factory at work. They also brought us to a few waterfalls that he thoroughly enjoyed. On Maui, we took a taxi to the kite beach. It was windy, but there was a cove just to the right of the kite surfers that was secluded and they had a blast. Use lots of sunscreen. On Kauai, we stumbled into the same beach that port adventures team was arranging. We just hopped a shuttle (tipping the driver was the only charge) and walked where he told us to walk. Disney had bought out all the lounge chairs, but the beach is public, so we could just hang out on the beach. It was beautiful, and the time was unrestricted. The kids loved it, and so did we. Otherwise, I think mine got really spoiled by the low kid ratio. They got TONS of character time, plenty of attention in the clubs, and the pools weren't crowded. It was an amazing trip.
The only other note, if yours happen to be young like mine, the time change was hard, particularly on our three year old. We changed an hour each night, three days in a row, and the same on the way back. Once we returned to our normal life (still another hour difference) it took a solid week to adjust.