The past two years, I've taken SQ (thrice) and OZ (once) on my LAX-MNL trips. OZ via ICN would get you there sooner versus SQ via SIN. Note that at ICN, i think SIN has a better lounge than OZ. If you dont mind having long layovers, SIN might be better. It's only 20 minutes to downtown and you can check out a few sites. At MNL, SIN has a much more comfortable lounge. If i recall correctly, OZ shares theirs with TG.

One thing about OZ in LAX, we had to be shuttled to the aircraft from TBIT. Being on J at that time, i get to be on the shuttle first, but they filled that shuttle to the max -- so once in the shuttle, they didnt care if i was in J or Y. It was a mad rush from the shuttle to the ramps for the aircraft. I dont know if that's always the case.

As for PR, i swore never to take them again-- except for their domestic Philippine routes (no choice domestically, really).