We've done both...but prefer Ohana. Why? It's not a madhouse and there's more time for character interaction. Also, the breakfast is served family style, so there's no going up to the buffet and worrying about missing the characters. Finally, we think the food is better too...all you can eat Mickey waffles, scrambled eggs, sausage, bacon, fried potatoes, and Hawaiian bread. Yum! We've gone to Chef Mickey's once, but we're going back to Ohana for our third breakfast this summer.
Oh, and you'll see Mickey, Goofy, Chip and Dale all dressed up in Polynesian wear...very cute!