you will have access to the new gold circle lounge at Dub.Ask for directions to it when you get there.It's quite near U.S immigration at Dublin.
You will be using U.S immigration and customs at Dublin,most U.S bound flights do.
Unfortunately there can be lengthy queues but the upside is you then arrive at Orlando as a domestic pax;no queue there ,just straight to the baggae belt and out to to your taxi.