I agree with everyone else who says that the cost of this exhibit is a bit much for what you get. It is a good way to burn an hour or two, but with the amount of money that MGM has (who owns the Mirage) the exhibits for the animals could be a bit nicer. They seemed mostly listless and bored in the small enclosures. The dolphins seemed a bit happier as they swam.
Even with kids in toe, don't expect to spend more than 2 hours here, unless you pay for a paint with the dolphins or be a trainer for the day package.