San Angel Inn is the sit down restaurant that is inside the Mexico pavillion (the one that was already there and is unchanged).
La Hacienda is also a sit down restaurant. It is the new one that is located on the water and beside/connected to La Cantina, which is the counter service. La Cantina is located where it was prior to the refurb.
San Angel Inn is pretty good, La Cantina is pretty good, and I have never been to La Hacienda.