We just got back and on our trip we ate at both Boma and O'hana and I'd say O'hana gets my vote. If you are coming out of AK it's a little farther, of course, but I think overall the food and atmosphere is better. Don't get me wrong, we did like Boma but the foods on the buffet are a little different so if you and your family prefer more traditional flavors it could be a problem. And I found the seating to be a little crowded and the buffet line tended to get long. But AKL is beautiful and the CMs were all wonderful.
But O'hana...ahhh. The Poly is so lovely and the ambience at O'hana was friendly and fun but not too loud and chaotic (like WCC can sometimes be). The food is served family style and the set menu included salad, shrimp in a sweet/sour type sauce, chicken, potatoes, veggies, and meats cooked on skewers. One comment - eating at O'hana is messy. The shrimp has to be peeled and the sauce on the chicken is sticky. They do give you stemed towels to wipe hands but if any one in your family doesn't like to get their hands dirty with eating then this might not be the place for you. And, as mentioned already, the dessert is spectacular - a bread pudding with vanilla ice cream and banana foster sauce. There is also entertainment for the kids during dinner. The mc is a polynesian women who walks around, sings a little, and leads the kids in cocunut races (sweeping coconuts with brooms around the restaurant) and the limbo. Lots of fun!
Dinner at O'hana is now one of our favorites and we will definitely go there again. We did enjoy Boma but I don't think we'll head back there anytime soon.