I wasn't impressed with Ohana breakfast. The juice was delicious, but the rest...eh. The food was cold. The eggs were runny. The sausage was OK. Crystal Palace was my favorite breakfast of our trip (Ohana, CP, and TH).
For breakfast I would definitiely prefer Crystal Palace over Ohana. CP has much more variety and it's worth the trip just for Pooh's Puffed French Toast.
Is all of your party adults? If so, I would prefer Cali Grill over Ohana for dinner. Ohana can be good, but it's just so loud and has so many kids activities going on that it can aggravating if you don't have kids who are partaking.
I haven't eaten at Ohana's for breakfast but the food at CP for breakfast I think is one of the best buffet breakfasts at disney.
As for dinner. I love Cali Grill. Its my favorite restaurant at Disney. You can't compare it to Ohana's, its not in the same class. We (me & my DH) didn't care for the food or service at Ohana's. A lot of people on here like it but I can't imagine those same people would pick it over Cali Grill, unless maybe they had kids (I didnt read the previous responses). But hands down CG is much much better. It is more expensive though if that matters, but I would pick so many other restaurants before Ohana's if price is an issue.