I've given it some thought of what I'll do after March. Delta or Alaska/American?
I've finally decided. I will not be a slave to miles. I used to have lots of status but now barely make the lowest status. I will possibly maintain status but may lose it. I'll fly either airline depending on the fare and schedule. When it's the same, Alaska/American will be my choice.
One exception is JFK-SEA. If I am not working but watching AVOD, Delta is clearly better. AA has it on only a few planes and never JFK-SEA. Delta's schedule is better because AA/AS has only 2 roundtrips versus DL having an extra noon-ish eastbound.