I echo some comments from other flyers. I too avoid CO due to the non-EQM issue. This often means that I book directly through a partner like NW or AA and am only on an AS flight if it codeshare for those airlines. (ie Most recently I booked a flight to IAH for a cruise and I opted to go with AA via DFW to get there.)

I don't know what type of cost study AS has done on this issue, but I would encourage them to revisit it.