Originally Posted by
nabeelj
If you're currently earning 1.5 Aeroplan miles per $, you would lose .25 miles per dollar by moving to the SPG Amex assuming you were smart about transferring.
It would really depend on your spending habits. Since Amex AP Plat gives 1.5x after $25K and you could get 1.25x on the SPG Amex, the OP would have to spend at least $50K on his Amex AP Plat to "break even".
However, SPG points are a much more valuable currency (IMO).