I status matched to DL last year from UA and was generally impressed with my experience, particularly staff attitudes. Unfortunately, after this week, I think I am done.
In the third hour of a mechanical delay on my CDG flight, I deplaned and had a friendly employee in the SkyClub rebook me on VS with a connection to an African airline in LHR. There was a better connection with EK, but the DL employee said they don't work with EK. At all. Nevertheless, I was happy to have an alternative that preserved my original schedule, even with a painful LHR terminal shuffle.
Th VS flight was lovely and the LHR terminal transfer was relatively smooth. I get to the transfer desk and the agent can't find my ticket. I show her the itinerary print out from the SkyClub with DL confirmation and ticket numbers. Still can't find it. She calls her ticketing desk, which says to call Delta. She calls Delta at LHR. No one answers. She calls VS, which says they can't help because it's a DL ticket. I try calling the Medallion line, but the wait is 9 hours. After more calls between various offices, they finally see the ticket, which is pending because DL didn't process it right. Since neither DL nor my corporate travel department will pick up, my only option to get on the connecting flight is to purchase a ticket.
Oh, and my return itinerary with a 006 ticket on AF-operated flights was cancelled. I like friendly employees, but an inability to get things right and recover from problems is unacceptable.