The OP flies primarily business class, so SQ's excellent PPS Club is relevent. However, one can achieve all the benefits of PPS Club membership while accruing miles to another *A FF program. The disadvantages to SQ's KrisFlyer program are: only 25% bonus for business class and only 50% for First Class, miles expire, redemptions require a relatively large number of miles, and KF (not SQ) customer service is poor.