Another more serious problem is that the YYZ-EZE/SCL route is very popular. They are finally adding separate runs to SCL and EZE for this winter (4/5 months) which will add capacity and hopefully more award seats but the planes tend to be quite full during the busy season. The flight is popular since many people like avoiding flying through the US if they can avoid it.

As far as the service and planes, AC will likely have finished the refurbishments within the next couple of months of all int'l planes and the service levels have been generally improving. So for NA airlines, they are pretty good. If you want SQ/OZ/LH business class service, wrong continent.