The biggest negative for me is the lack of flights and connecting options from the Bay Area. I often consider switching to UA simply because I find myself forced onto partners for many of my flights, even for destinations served by AS. It is very difficult to get to any of the east coast destinations from the Bay Area on AS (without taking a redeye) and CUN is not an available destination, even with the AA LAX-SFO codeshare. The service between the Bay Area and Sothern California is also pitiful. I would love to see AS actually compete on the SFO to SoCal markets, which are pretty much completely dominated by UA and have no LCC competition. As it stands, AS can't compete in this market because it is primarily a business market and AS just doesn't have sufficient frequency to attract any business travelers.

The biggest positive is the flight attendants and the people working in the reservations centers. The AS FA's are, IMHO, the best in the U.S.