Here's the skinny... DC is expensive.. and a scheduled date that is pre-reserved. However, buying a DC ticket also gets you 7 days access to SW and Aquatica. You can upgrade to include BG Tampa if you wanted. Inside DC its an inclusive experience, with paid opportunities to do a dolphin swim and a dive helmet piece. The dolphin swim is inferior to those you would do in the Bahamas.. it's more like a 'dolphin encounter' tho you can upgrade and do the swim where they drag you. Instead, do Blue Lagoon in Bahamas and get to do things like this..
So it's expensive if you only do DC.. but if you do Orlando.. it's great. We did I think three days in Orlando... One day at DC, One day at SW, one day at Aquatica.. and we'd go back to SW at night so the kids could do their repeat rides, etc. We also got to see the Christmas stuff at SW because it was November.
A day at DC.. even after doing the cruise... will make you hate everywhere else because the inclusive nature, limited crowds, etc again brings back the idea of SERVICE... not just consumption