I'm a Seattleite, and while I think AS generally runs a good airline, I don't understand the level of loyalty and fanboy-ness that many Seattleites seem to have toward AS.
Many years ago (like in the late 80's and 90's) AS may have had a substantially superior product, especially in terms of food and sometimes employee attitude. Today they generally run a good operation, with good on time performance and completion rates, and mostly their employees provide good service. But it's really not that different than any other airline, and just like on any airline there are good employees and bad apples and some that go out of their way and many that just go through the motions. And AS's food and hard product have lagged, with no economy plus-type seating, no in flight entertainment (other than the lame DigEplayers for rent), no power, tight seat pitch and limited recline in F.
I do fly AS but it's not dramatically better than others. My favorite feature is no change fees for MVPGs and the fact that they have nonstop to a lot of destinations, although DL now has most of the ones I care about covered. I don't doubt that if the UA move to revenue based earning holds, that AS will go that route as well, so the main difference between AS and DL will be that AS still has no change fees.