Either one would work I think, but the view at California Grill is spectacular! Do you have any small munchkins in your party, though? [Standard every child is different disclaimer, but] They might enjoy 'Ohana more. If it's adults only, then I definitely vote for the CG.
Keep in mind the price difference as well, if you're on a budget - 'Ohana is ~ $25pp before tip, CG can be double that for appetizer, entree and dessert.