To my mind the main question is how much do you fly today on non-rewards, miles-earning airline tickets on Air Canada and AC partners? If you do this regularly it makes sense to stick with an Aeroplan-affiliated card as all the miles go into one 'bucket' - The miles earned from flying, and the miles earned from the loyalty card.

If you don't earn miles from flying, or fly regularly on non-partner airlines like Alaska or BA or whatever then you can basically choose whatever you'd like, i.e. Avion, Airmiles etc. because there's still only one bucket of miles.