Originally Posted by ffsim

Excellent summary!

This is probably a discussion better suited for the Amex forum, but some cards (e.g. Platinum) earn 1.25 Membership Rewards points for every dollar spent while others (e.g. Gold Rewards) earn 2 MR points in certain categories and 1 MR point in the rest.

If one has a detailed enough understanding of how one's money is spent, one can maximize the use of both cards since MR converts 1:1 to Aeroplan as you said.