For us, it's an easy decision -- Tusker!!!! It offers you a great buffet with lots of selection, the characters are Daisy/Donald/Goofy/Mickey all in safari clothes, you can get into AK early and be first on Safari at rope drop. We always make an 8am ADR on our AK day.
IMO, the only reason to do Ohana is if you really like Lilo and Stitch. I think their breakfast offering is pretty limited and not really that yummy. I think there are other bfast character meals to do on your day before MK (like CRT, CP, Chef Mickey, 1900 ParkFare)