I can't speak for the one at Disney, but we've been to the one in Kansas a few different times. From what we've experienced, the food is fine. Not particularly memorable, but just fine. It's definately more of an atmosphere experience than a "My goodness that's a fantastic burger" kind of place.
That said, my 2 year old DD loves dinosaurs, and it about scared her pants off. We had to take her (untouched) food to go and get her out of there. She was already nervous, but actually handling it okay until the guy in the dino suit walked up to our table. She generally likes characters (well, Chuck E Cheese anyway) but she was pretty sure that "Sharptooth" was going to jump down and eat us all anyway, so when the guy in the dino suit came to our table, it was all over.
She did enjoy build a dino though. And rather than the cute pink Brontosaurus I thought she'd pick, she picked the Velociraptor with the 3 inch claws. She tends to sleep with him at night on occasion. I guess she figured he's a good guard dino.