I think the Krisflyer AMEX earns 1 mile to S$1. The Platinum charge card with "double points for life" is 1 mile per S$1.25. With 10x points at certain stores, it's 1 mile per S$0.25. I'd advise against going for the Platinum charge card unless you're getting a really good deal (ie. fee waiver) or the company's paying. Only feature worth having is the PTS but the service's been atrocious lately. The Plat credit card is better value with many of the same benefits. The PPS card is OK too but it's less-featured than the other Plat cards. Probably worth checking DBS out too, if they still have 4x points (1 mile for S$0.6) on their black AMEX.