The food is good at both. It might depend on if you want a buffet or order off a menu. The adult buffet at Boma is $14.99. They had some African dishes, American breakfast items, fruit, and breakfast breads. They also had a wonderful roasted pork loin. We arrived at 9:30 and the restaurant was not busy at all. The buffet stayed fully stocked even though they were not busy. It was a nice leisurely meal. All of the fruit was fantastic. Kona has Tonga Toast, but I really don't remember any other specialty items. The Tonga Toast is very good, banana stuffed toast covered with cinamon and sugar. I think breakfast at Kona was probably about $9-$11 per person.
While I enjoyed both, if I could only go to one, I would choose Boma.