Delta is Delta
As a passenger, if my ticket says Delta, the ticket counter says Delta and the plane paint says Delta, it is a DELTA flight.
I am upset enough already to discover at the last minute I am flying on a code share with another airline that I have NOT chosen.
Finally, I dont give a damn to know who is the crew real employer, who is really servicing the plane or who is really cooking the food. I sure know who I am going to blame or congratulate (I do that too) for the quality of my flight; it is the company that sold me the ticket.