I can see why a first time tourist in Bangkok (with a thick wallet though) might give 5 out of 5 to that place.
The location is nice, the short boat ride to cross the Chao Praya "soooo typical" and the show was quite OK (but nothing exceptional). And the food is tailored for their palates.
I was there for an official function with local and foreign VIPs. The local VIPs and us, who have been living here for some time, really though the food was not at all what we would expect from a MO restaurant. Of course they can't make it a spicy as Thai would love, but try at least to make it less bland!
The service was OK, but again, this is Oriental, i would expect a bit better, And the show... maybe I am partial as i have seen too many over the years, but i would have expected at least some comments in English for the foreign guests, explaining exactly their performance instead of relying only on a the pamphlet.