I've done it a couple of times. The last time was about 8 years ago, though. But from what I understand, it hasn't changed much over the years.
I really enjoyed it! The food was much better than at most 'dinner theaters' around town. High quality, very palatable Polynesian inspired dishes. Even being as picky of an eater as I was then, I had no trouble finding something I liked and thoroughly enjoyed all the food!
The show itself was very nice, too. The fire dancers were particularly impressive! I found it to be of high quality, not hammy or campy like other Orlando dinner shows. I can't say how 'authentic' it was, as I've never been to Hawai'i.. but my neighbors /were/ from Hawai'i and worked there for many years (a couple of the ladies worked as dancers and the father was VP of Food Services for all the SE A-B parks at the time).
Somewhere I have some old 35mm photos I took, I'll have to look for them and perhaps scan them in at some point soon.
I definitely recommend it, personally!
=)