Number one disappointment has to be Ohanas. These boards mention this restaurant in reverence, and you'll be flamed to death to say anything bad about it, but we've been there several times, and it has been awful. The meat is overcooked and has the consistency of fine leather.
It is so popular, they don't even try to seat you anywhere near your reservation time(we were seated at 8:10 for a 7:00 reservation last trip in April) , and when you do finally get seated, the service is rushed--they just throw the food at you as fast as they can to turn the table over.
It's like the Emporers New Clothes, I guess--the legend of this place supports itself.