I have several times. It is great and perfect for the theme park. What a relaxing place after all the hecticness of the parks. It is pricy though. If you really want to get up close and don't mind waiting, you can ask for a near display tank seating. However, any seat in the house has an awesome panoramic view of the tank.
Oh, and the food is good too. Mostly seafood, though, with a few landlover choices. Plan for either an early lunch or late lunch to avoid big crowds, but if you plan to go next month, everywhere in Disney will be a big crowd. You must make reservations for the busy season, and its a good idea to do so at other times as well. If you haven't seen the Living Seas, then you are in for a real treat!