Hi everyone. I opened a similar thread at United and American forums, and believe that it relates to the original here. I'm sorry if some questions or comments were addressed already by you:

Ladies and gentlemen, my sincere apologies for the long post, I couldn’t make it shorter.
Thank you in advance for your time and help to those that will read it and provide feedback.

Got CJOs from United and American… Anxiety for making the right choice is above happiness at the moment.
I’m flattered by this opportunity, both companies have amazing positive aspects and the treatment during the selection process was excellent, it’s so hard to pick one over the other one. I believe that both are great places to be, a great group of people that are welcoming us.

After 16 years flying overseas, I might be a bit out of touch with what’s going on in the industry (the specifics, the plans, the contracts and rules, etc.)
I’m reaching out to your good hearts and expertise, looking for some guidance.
I have “only” 15 usable years ahead, so not much room for wrong decisions.
Captain in a wide body now, it has been like this for more than 12 years.
I will be moving back to wherever my base will be (places that don’t see snow, MIA, LAX, SFO, IAH, DFW or LAS), I will never commute. My priority is QOL, no money (blocks of days OFF together to take care of some family overseas, roster control, less flying). And yes, getting back to the left seat of a wide body for some international flying before a retire is a plus (I know it might never happen in my remaining 15 years).
So…Any advice and inputs from you ladies and gentleman will be highly appreciated.

What I see is as follows ( obviously today, nobody knows the future):

American retirements are more, but no big plans of growing.(less potential years as a captain maybe?)
American international presence seems to be getting smaller( harder to get the wide-body?)
American treatment pre, during and post interview was more friendly than United’s one, not sure if company culture is much different once on the line ( better company culture or environment at American may be?)
United orders and growing plan are huge (is that too risky or an unrealistic plan to rely on?)
United reserve rules are bad people say (shouldn’t I care anyway if I have a line right away or reside at base?)
United upgrades are fast (only if you are willing to get reserve?)
SFO at United can get you a line right after training (it is that expensive to leave there that nobody wants that base or are other reasons?)
Both airlines at LAX and Texas, places where I can move. (Any big differences for example between AA and UL at the 737/LAX? Or 737 IAH/DFW?)
“United hired 3000 last 18 months, wave is over” people says…(how is the “wave” at American?)

Overall, I am inclined to believe that UNITED is a better option based on my priorities and speculations. Thinking about moving to LAX or SFO for a good movement on the 737 right seat, might never see reserve, and wait there for descent seniority for upgrade holding a line or WB FO line holder. Sounds like a realistic plan or am I day dreaming?

Girls and guys, sorry again for the long post and thank you so much for your inputs and helping me gathering different points of view and opinions for my life/professional decision.

It is a pleasure and joy to get back to the US and start a new chapter in my career.

Happy landings

Tanga