The only other 121 job I'd leave for is FedEx. IF they opened their Alliance sort facility as a crew base. If you live in base, are year 3 pay or above, the 'golden handcuffs' get quite comfortable!

Edit:

IF I commuted, I'd be looking for domiciles I could live in (1), seniority/pay comparisons (2). If I was going to commute no matter what - FedEx without a doubt. Two close friends there, they both love it a lot more than I like AA.