UA star alliance is great for availability to panama. in fact star is the only choice to go to David panama. also booked great trip from argentina to lax, stopover to Disneyland, Amtrak to Denver, then on to map and return for family of 4 to come to my daughters wedding. couldn't have done the stopover or open jaw on amer or delta. on the other hand delta had direct flights for 5 of us msp to ixtapa this spring. american had the best flights for 4 of us map to Hawaii last year.