I've never eaten at the cafe, but on x-mas eve, we took our break at the Kona and it was great! Sushi, steaks, and the curry shrimp soup (that might not be the name) was awesome. Plus we got to have wine!
Kona cafe is very good. The last few times that we have been to GF cafe it hasn't been good, some stuff okay but not all & just okay at that. And the service isn't too great there either, any of the times that we have been there.
I think the Grand Floridian Café is one of the best lunch spots in the World. I would save Kona for another meal. I like going there for dinner, when the sushi bar is open.
We loved our lunch at Kona, the food and cocktails were to die for...I like hanging at the Poly in the afternoon when everyone is at the parks, so nice and quiet and relaxing