My biggest problem with Kona is that if you are there when the atrium is busy (i.e. when a herd of people are waiting to get into 'Ohana) the front half of Kona feels "invaded" by all those people waiting, because the front is completely open.
The Wave is tucked down in a lower floor of the Contemporary, but it's vaguely-sort-of-hip environment is sort of interesting.
If I had my kids with my, I'd go Kona. Adults, I'd lean to the Wave. I thought the food there was just a little more interesting than your typical "standard" WDW TS.