I'm really not following your math here, but assuming a 2.7% fee on all foreign transactions with the SPG card, I would safely toss that card out of the mix.

Personally I think the sapphire preferred card is the better deal, as you get 50k points for free to sign up, and 1 points per dollar spent, as well as a .07 point bonus at the end of the year (so effectively 1.07 pts/$$).

But I think it all boils down to what you're gonna use the points for. Sapphire Preferred transfers 1:1 into CO and BA, after the annual bonus, the effective rate is 1:1.07 whereas SPG transfers 2:1 into CO/UA and 1:1 into BA/AA. For every 20k points you transfer SPG gives a 5k bonus, so the effective ratio is 2:1.25 for CO/UA and 1:1.25 for BA/AA.

All SPG transfers are listed here by the way:

http://www.starwoodhotels.com/prefer...tner_list.html

Now assuming that you're gonna go the BA route for the sake of comparision, Sapphire gives 1.07 miles per dollar, whereas SPG gives 1.25 miles per dollar. The difference is .18 miles per dollar under optimum conditions. However, SPg charges a 2.7% fee on top of this. So basically, bonuses aside, for $20k spend your break down is:

Sapphire: 21,400 miles, $0 foreign transaction fees
SPG Amex: 25,000 miles, $540 fees.

personally there is no way in hell that 3,600 miles is worth $540 in fees so that is why I would not give a second look to the SPG card and would rule it out immediately.


EDIT: Now I missed the part about you staying at SPG properties for $30k/yr. As SPG platinum you STILL get 3 spg points/$$ spent regardless of how you pay. But by paying with your SPG Amex, you would get 1 extra point per dollar. So basically what you have to decide is if 30,000 extra SPG points is worth spending an extra $810 ($30,000 * 2.7% Forex fee). In my opinion, no it is not. But if you value them at $.05 then it would be to you. But again, look at how you are going to SPEND THE POINTS and decide. If transferring to CO, then there is no way that SPG will ever be worth it.