BOMA...
We love Boma for all meals...and it's one of the only dinner buffets we do enjoy!
We tried Ohana for the first time for dinner (we have had breakfast plenty there) on Christmas Eve 2015...and it lost for us...but we had a very late ADR, waited for about an hour to be seated, they were out of bread, the wait staff was barely there, we were very tired. SO we are giving it another try with a very early ADR in 2 weeks...I so want to love it and I do love the theory of it...but Boma never feels crowded even when it is, there is a ton of food to choose from, it is always good and plentiful and we have never had a service problem...we have even had a waiter give us to go cups for drinks and food left on our table when we were leaving (I did not think any buffet did that!).
SO if I had to choose one it would be Boma at this point.