The entire point of this 12-page (and counting) diatribe is that this decision is different for everyone ... and it's not just the difference between AA and SWA as the original poster asked.
Case in point ... I left a moderately senior CA position on the best-paying equipment at a sizable regional to come to US Airways 2.5 years ago. For me, for a variety of reasons, the decision was an absolute no-brainer, and I've never regretted it. I'm now based at home, have nearly 400 underneath me, and am about to make the most money I've ever earned in my career working for the largest airline in the world with the oldest pilot group in America ... in other words, relatively rapid advancement in an industry where advancement is the closest thing there is to job security.
I don't say that to brag on myself. I have friends who are shackled by the so-called "golden handcuffs" at regionals and can't/won't leave. I have friends who have gone overseas to the Cathays and Emirates of the world. I have friends at pretty much every airline in the US.
Each and every one of us made the best decision we could at the time for our personal circumstances - weigh the risks and the rewards, then you roll the dice and take your chances. For some it will work out, and for some it won't. We'll all know after we retire. But if you want a prediction of the future, you're barking up the wrong tree asking a bunch of airline pilots about it. This entire forum proves only that we can't agree on much of anything ...
Pilot 1: San Francisco is west of New York.
Pilot 2: No, it isn't. I can prove it!
Pilot 1: BS. How?
Pilot 2: Take off from New York. Fly east. Keep going long enough and you'll find San Francisco.
Pilot 1: Yeah? Well, my airplane is faster than yours.
Pilot 2: Sure, but my airplane is bigger.
Pilot 1: Well, my wife is hotter.
Pilot 2: Yeah, but my mistress is a better cook.
Pilot 1: F^(&^%*& you!!
Pilot 2: Scab!!