Stick with UA. If you go Krisflyer, you'll have to pay fuel surcharges when you redeem award tickets. And, because of Star Alliance, you have the choice of SQ, ANA, Asiana, EVA, Thai, Turkish, LH, Swiss, etc... Definitely, lots of choices. There is a 1 downside, like, no direct *A flights from Hong Kong to Philippines. Other than that, I've found *A to be the best to stick with, hence, UA.