Cynics could point out that the construction of the dome a few years ago cut into the overall size of the dolphin pool, but visitors are overwhelmed by the experience and it is possibly full of enrichment for the dolphins that swim overhead.
I believe that there might be 3 pools, but the dome is located in the large performing pool while the other one or two areas are smaller and not necessarily for shows. There should be some other photos of the Oceans complex in the ZooChat gallery.
I think sharks have the "wow" factor because dolphins are alright to see but sharks, thats another story! It looks almost like a shark tunnel! I would prefer sharks over dolphins.