Hi there is loads of feedback on the dis boards about this, the most popular is the royal swim and i understand the best deal is to book direct through chankanaab park where you can stay and play all day, if your going to orlando first we did discovery cove dolphin encounter which was awesome, yes its more expensive but you stay all day at a gorgeous resort, numbers are limited , a full lunch is included , you get to snorkel with tropical fish and swim with stingrays and you also get 7 days admission to seaworld with the price, if you are doing the non swim you get everything except the dolphin part.
Hope this helps