Air China releases an immense number of award seats, including First Class in abundance. While every Star Alliance frequent flyer program, including Aeroplan, should be able to book those Air China award seats, Aeroplan has purposefully blocked all Air China seats for quite a while. As of today, it looks like Aeroplan can now book Air China awards (again)! This is great, especially considering Air China flies to Vancouver, Toronto, and Montreal, and there are no fuel surcharges when using Aeroplan. Note that the flight between Montreal and Havana cannot be booked.
Let Awarding Canada deal with your award booking needs.