Ultimately you should look at both menus to see what appeals most to your family, but for us, we prefer The Wave. We used to be big fans of Kona but hadn't been there in a few years. We just ate there 2 nights ago, on the last night of our trip. It was so loud we could barely hear each other speaking and unfortunately, the food and service were mediocre. The bread and butter were still wonderful, but nothing else was.
The Wave on the other hand is a must do for every trip. The food is great, and the atmosphere is much quieter than Kona. It is really a hidden gem, like so many people have already said.