It's not similar to WDW. It's $19 for adults/$9 for children for one park, and $23/$11 for both parks. For that price you get a wrist band which entitles you to all you can eat in the parks only for that day. For another $7 you can get a sipper cup which gets you unlimited drinks to go with the all you can eat.
It is only good at the ready-to-eat places, so Confisco Grill and Mythos are definitley out. Personally on vacation we eat light during the day and like to go out for a nice dinner. It just wasn't what we were looking for. I LOVE US/IOA so much better than WDW for our family, but I think WDW has US/IOA beat with its dining plan.