My wife and I used PMUs to upgrade on our BWI-JFK-FRA and CDG-ATL-BWI itinerary last year. The front counter employee at BWI who waited on us, Miriam, an excellent and efficient employee there, took 20 minutes to process the coupons, and this is not a knock on her--it took that long to get everything properly entered on her computer system, including two telephone calls to DL computer staff. That struck me as bizarre, as our reservation had been changed the moment the DL SMS reservationist confirmed over the phone that the upgrade was successful and was entered into the system, and we were given seat assignments in the premium cabins (BWI-JFK was a DHC-8 and was not an upgrade flight).

DL either needs to automate these coupons or have a much simpler procedure for their front counter employees.

We're using PMUs next Friday, and our originating flight at BWI leaves at 0600. This means we are going to have to get into the airport at 0430 to make sure that we get our coupons processed in order to make the flight.