Alaska hires great people, I mean it! I really admire the culture, but if I were in the job market I don't think they'd be my number one based solely on career progression.
There are lots of young Captains flying around so attrition isn't going to be a huge upgrade producer. That leaves growth. With one fleet type (the same one SWA is flying), DAL growing in the home-drome, and UAL recent order for almost 100 737-700's growth at AAL may not come quick enough.
Career progression would give me pause, but what a solid company to work for otherwise.