AC is better if you want to redeem tickets SIN-ChinaUA puts China and Singapore into two different regions, and a SIN-China award needs 40k; while AC puts China and Singapore into the same region, and a SIN-China award need only 20k miles... That said, UA is better if you fly 50k miles or more in a year, because they give 100% bonus miles when flying United metal, and more importantly, their economy plus seats...