Ohana dinner is great! Delicious food, check out the menu, open grill, entertainment. An absolutely delicious and fun experience. And the Polynesian is a great resort to visit if you have never been there. At about 6pm, most nights, there is fire juggling and drumming by performers from the Spirit of Aloha who do a welcome the night ceremony... That's at the main lobby entrance, same building as Ohana.
On the other hand... Ohana breakfast has characters - Mickey, Pluto, Lilo, and Stitch. And the breakfast food was very good... especially the warm pineapple-coconut bread...yum.
Don't know about Boma. Kona Cafe is boring and nothing special.... at least compared to Ohana.