Remember that that is about the same price at any other dinner show, like all the mystery dinner theaters in our area, Medieval Times, etc that are everywhere - so put that way, it's not really too bad for a great night out and a special treat.
I have been twice, both as children, and they are some of my few memories of family vacations to WDW. They were lasting - and I know that I enjoyed myself. I can't wait to take my children there someday.
I think if you like having a good time, involving the family, eating southern food (fried chicken adn the such), and some corny humor - you'll love it.
Think about doing it on a day in which you don't do the parks, so you're not paying for both. LIke, the first night you're there, and you don't want to hit the park immediately. Its a great first night activity =)