ANd there I think you have the best advice, go once & form your own opinion! While I can appreciate wanting to hear what others think to help make up your mind, if you read about a restaurant you absolutely love & have a great experince every time, you're still going to see on this board some who do not share your enthusiasm.
So if you're on the fence, it sounds like you do want to see it & want us to talk you into it. So go for it! I too have always wanted to give the luau a try & have finally gotten around to booking it for our next trip.
Me, I enjoyed the cheesiness of the Hoop De Doo so hearing the luau is cheesy is right down my disney alley. Why not I say