We have always enjoyed the food at 'Ohana, especially the appetizers and dessert, but honestly, they bring out so much food that everyone is bound to find something they really like. If something comes out cooked not to your liking (like the turkey is dry or the beef is too rare, for example) you can ask your server to bring more. I think you are better off eating early, so you don't have to wait to long for a table and the meat hasn't had a chance to get dry.
We've enjoyed great lunches at Kona, and I've also heard great things about The Wave.
We didn't enjoy WCC, must have been an "off" night, but it is a favorite of many and very convenient by bus or boat to MK.
I think your kids would best enjoy 'Ohana or WCC out of the TS sit-down restaurants outside of, but near, MK.