You can only earn one or the other on each stay.

On each stay you can choose whether to earn points or airline miles.

But why earn airline miles directly? You only earn 500 Aeroplan miles per stay right now (they crossed out 350 and put 500, so I don't know if it's a temperary promotion or not). So for 2 totally separate stays, you'll only earn 1000 Aeroplan miles.

However, with the promo from now through Nov 11, any two separate stays (if earning points) earn 8000 points. 5000 of those points turn into 1000 Aeroplan miles, with 3000 points left over.

So if you do 4 separate stay on points, you'll earn 16000 points which can transfer to 3000 Aeroplan miles (with 1000 points left over). But if you do 4 separate stays on miles, you'll only earn 2000 Aeroplan miles (with no points at all).

So why bother earning Aeroplan miles directly (during this promo*)? If you really want Aeroplan miles, still earn points on the stay, and then transfer points to Aeroplan later.

But 16000 points may get a you a free night at some >$100 hotels. How much value with 3000 Aeroplan miles get you? So even though you can transfer Choice to Aeroplan, you may want to think about whether that's the best value for your Choice points or not.

* Earning Aeroplan miles directly might make sense once this promo is over after Nov 11 (or once you know you only have 1 stay remaining before Nov 11, and you'd need 2 stays to get the next 8000 points). Without the promo, you'll earn more Aeroplan miles if you earn them directly, even though during the promo you'll earn more Aeroplan miles if you earn Choice points and later convert them Aeroplan miles.