I have done the luau a few times, the old one, the kids one, and the new one.
Everyone in my family loves it, however I'm not a fan. I find it boring. The Hoop dee Doo is sooooooo much better and Cirque de Soliel is a million times nicer.
However, if you are staying at the Poly, go for it. It is a good way to get into the Poly spirit.