I am PM on DL and MVPG on AS. If you are going to leave DL/NW, definitely switch to AS. You will get upgrades on DL later this year, already get them on NW, and you can earn miles from AA, CO, DL, NW, and a bunch of international carriers. Also since you fly out of SEA and PDX, you can get direct flights pretty easily.

If I were you, I would do a status match to AS and give it a shot. Takes about 1 week for it to go through.