Originally Posted by
ethernal
It seems like United is your logical choice. The destinations you are traveling to most often are United / Star Alliance hubs and connectivity will be far better.
Why does connectivity beyond the destination matter? DL serves SFO, GRU and FRA non-stop from JFK. EWR-SYD requires a connection, too. Do you want to wager UA is done with Polaris refits before Deota One suites are complete?