i would compare Alaska's route map and schedule to Delta's, and status match to the better program for where you need to fly. This is Alaska's big hub after all. With AA -- your nearest hubs are 3+ hours away, flights to SEA are often too infrequent to be of good use for connections, and you often have to back-track or fly in two separate programs compared to a nonstop flight. This makes IRROPS difficult. I favor Delta because of their IFE/hard product and flight performance compared to Alaska (or AA), but whether this matters all depends on flight frequency where you need to match work timing and IRROPS needs. Alaska interestingly has better Asian partners if that matters.
My problem is similar at BOS. AA seems keen on continuing Oasis, not investing further in lie-flat transcontinental seats having half-heartedly trying LAX-BOS, and often leaving me with sub-40min connections @ PHL (no shower, running to/from Terminals B and F) or CLT to get anywhere that isn't already a hub. If not for the outstanding Asian OneWorld partners, Delta has been calling my name.