I was look at flights on FBC today for our upcoming cruise in October. For MIA to FCO I could choose the ITA non-stop flight for $50 (yes that's the correct price) or the exact same flight but labeled as Delta but operated by ITA, same flight, plane and itinerary for $200. If you looked at the details, the ITA flight did not allow seat selection in advance and only 1 checked bag and no carry ons. The Delta flight allowed advance seat selection, 1 checked bag and 2 carry ons. I also think you can get Delta Skymiles for the Delta flight but not the ITA branded flight.