Never again. Arrived from a domestic PAL flt in T3 at 1330 and nearly misconnected on a SQ flt at 1650 out of T1 from the same airport! Disgraceful that there is no reliable terminal shuttle to T1. And that they extort money from you when you take a taxi for the transfer and it takes an hour on the road to get to the other terminal. Whereas if you transfer to another PAL flt you can get a shuttle that stays on airport grounds and avoids the traffic.