Originally Posted by JALOO5-Flyer

Note neither AAdvantage status nor domestic First grant lounge access for North American (except tcon and MEX) itineraries, which makes AA status not as appealing compared to other ow status. An oneworld status is definitely nice for HKG departures for accessing HKG lounges.
Talking about points - it really depends on how you collect them. You do not need a JAL status to upgrade yourself with points, and you could always get massive JAL miles by converting SPG (now Marriott) points. I sometimes prefer crediting to AS on some airlines offering up to 300% bonus, as I could just transfer SPG to JAL if I need them.
If you consider upgrade a big factor, go with AA. AA is space-available upgrading while JL likely only op-up (which means less change getting upgraded... unless you are always on oversold flights). Also you can confirm or standby upgrades with SWU while it is not a thing on JL.