When parked at JFK at gate 1 I see a notice on the baggage/conveyor belt wall that says something like "premium bags first" I also see some of those big metal boxes/holders that are soemetimes labeled is such a way that makes it "Premium" I think it depends on if they baggage handlers are deciding to desginate a metal holder for the premium bags and load that last on the plane so that it is first off when off-loading, and if they are on schedule or not, and when you check-in etc.....