I would go with the character breakfast (even though it's somewhat pricey).
When we went last November, we LOVED Ama Ama for dinner but thought it was just okay for breakfast. Don't get me wrong, the food quality was good, but IMO, not that much better than the character buffet at Makahiki and the buffet has so much more selection (and we thought the quality of the food at the Makahiki breakfast was above average for a Disney character breakfast and we've been to most of them at WDW and DLR).
The biggest advantage Ama Ama has over Makahiki for breakfast is that it's quiteter and more relaxing (I always find full-service restaurants to be more relaxing than buffets). But Makahiki is more fun and exciting and the selection is just so much better (without sacrificing much quality). Even if you're not into characters, I think Makahiki is the better choice for breakfast, even if it will likely cost you somewhat more than Ama Ama.