The two are nothing alike; the only thing they share in common is that they're both at the Poly. Both are very good for very different reasons. Ohana is a fun, upbeat, and festive meal. DD17 may not want to participate in the activities which are more geared to younger children (hula contest, coconut sweep contest, etc) but it is entertaining just watching the goings-on. Food, as PPs have pointed out are meat-on-a-stick-fests; as much as you can stomach and no worse than other similar restaurants at WDW. Kona on the other hand, although it can get busy, and tables can be a bit close together, is much more relaxed and the food is excellent. In fact, I think it's one of the 2 hidden gems for dining at WDW (the other being Grand Floridian Cafe). Summary here I guess is if you're going for entertainment, go Ohana; if you're going for food, definitely KC.