You've gotta do what works out best for you, for sure. But I've got to throw this in too: Using AA miles for long-haul F redemptions on Etihad and J on Qatar are over the top good. Knowing how difficult it is to get AA miles in Canada, I see this as a chance that will quickly end, but could get you a truly aspirational redemption. I fly DFW-AUH-CAI in Etihad Suites (to AUH)/J to CAI (there is no F cabin on this leg) in April, and it cost me $7 plus miles. Seven!

Or...if you're more into simple domestic redemptions, using AA miles to book one way direct to Canada from the US will cost you $5.60. That's a lot less than Aeros for the same redemption!