I dont know what AA uses..Im guessung a 757 or 767. Of course they have more F room in those and Im sure you were aware of that before booking a flight on a 738 so Im not sure how this is a justified comparison
I flew LAX-LIH/HNL-LAX on an AA 757 back in February (report at
http://www.flyertalk.com/forum/showthread.php?t=813772) and, having experienced transcon F service (but not Hawaii) on AS, I'd say that I'd probably opt for AS over the AA narrrowbody. AA does send some 767s with international business seats to the islands, in which case they'd probably get the nod, but AA 757s have a pretty out of date F section and are nothing to write home about. And I think the AS food service and digeplayers sound slightly better (AA just has overhead monitors).