Disclaimer: Second hand info and have no dog in this fight, I work at neither but have close friends that work at both.

First of all, toss the culture argument. Ship sailed decades ago and even if it hadn't, hot pants and room parties don't pay mortgages. (more likely lead to a ruinous divorce...or two).

On to what really matter$... Having worn many suits, the largest factor for me, by far, would be stability, especially if I were looking out 30 years. All the quick upgrades and WB flying mean zip in the unemployment line. There's no telling what the future holds but if the past is any indication, not to mention balance sheets (AA has HUGE debt and exposure with intl. LCC competition), WN is a hands-down favorite. Granted, past performance isn't always a forecast, but WN's domestic focus and a 40 year unbroken track record of profitability with zero layoffs is certainly more reassuring than the chronic boom-bust cycles of AA. A recession is coming and virtually guaranteed to occur more than once during the 30 years you have left.

While the Max is certainly a concern, it's likely a temporary one, and WN is still managing to make profits in spite of it. Hook or crook, WN's management will surely overcome this, one way or another eventually. While this will further delay an already long upgrade time, 4 stripes aren't quite as critical to income as many might believe: senior FO access to premium pay (150% bump) trumps junior captain (reserve) access (~130% bump over FO at straight pay) . Although premium has dried up, my FO friends at WN, admittedly Ho-Ho's, were making more than junior NB captains at the majors. Some 'Tournament' senior WN FO's allegedly cracked the $400K mark in 2018. Those days are over --for now, but with WNs flexibility and rigs, even mid-time FOs can still do quite well ($250K - $300K) with some creativity. Under the current contract, 2020 FO rates will top out at almost $200/hr (5 yr ~$170) which, IF times return to what they were, could still be quite lucrative. I understand even a slug at WN can easily crack 120 hrs/mo with plenty of days off. WN has always been associated with hard work but I'm told that has softened and even mid-seniority FOs can hold lines containing turns and 2-day trips, many of which only have 2 legs per day(?). Perhaps those who work there can chime in, but that doesn't sound rough at all.

All that said, if WB Intl flying is a priority over stability, you might not be overly thrilled with WN. No doubt those schedules, destinations, pay, and long overnights are tough to beat, and previously took years to hold. Although most at this level care more about $$ and schedules, if the 'prestige of command' is a must, than AA is probably a better choice.

Enviable problem to have. Both are good, but very different choices. Time changes everything so it's kind of a WAG any way you roll the dice.

My 2 cents. Again all second hand, but your 'Pro/Con' regarding stability is an important one that most would agree puts WN out front. Best of luck with your decision.