Thanks for the info.
I took the plunge and got the card which I received today based on exactly the same analysis about ROI at least on 1st year despite the lack of travel cancellation insurance. I immediately called Amex and inquired about the IAP for the specific route which came at SQ=$1,638.03 instead of $1870 (10% with fee) directly through the airline and CX=$1,279.73 (8%) instead of $1444 through the airline, not including the $39 Amex ticketing fee. The fare rules are a bit different in such that Amex is non-refundable ticket with cancellation fee equivalent to the airline. I was not sure what it meant but Amex said I can cancel for the fee and the taxes will be refunded but the ticket base fare will be credited to my account through Amex to be redeemed on same airline. Not the best deal but no bad either.
CX would be all legs on new A350 and SQ all legs on 777-30ER. I am leaning toward SQ for schedule preference for my layover in Hong Kong but not set yet. Do any of you guys would suggest CX instead.