I live in Kansas City and our T-Rex restaurant has been open almost 2 years now. It is a cool place to experience - that said we 've eaten there three times and I've yet to be impressed with anything I have ordered.
They are a bit expensive. They are owned by the same people as Rainforest Cafe - so if you've eaten at one of those you'll know what to expect in terms of cost and type of food.
Now if ds requests to go there (he's 4 and currently obsessed with dinos) we will go up just for dessert, or just for an appitizer. You still can sit there and experience it all without having to spend money on a not so great dinner.