In a nutshell, MTL seems more agency focused, while TOR best options seem to be indy SP. Granted, Ive been to TOR twice, so Im not a seasoned pro by any means. Perhaps others came chime in
Toronto has a big agency scene, bigger than Montreal. The biggest agency there has over 100 girls on the roster. Whether the indies there are better choices is a matter of personal preference. But there are plenty of agencies, and just more variety in general (e.g., lots of European SPs compared to Montreal, more specialty agencies like Asian and fetish), at the cost of a more sprawling scene not as centrally located.
The agencies in Toronto also tend to offer more options than the Montreal ones. A lot of them offer 30 and 45 minute appointments for example. Some of them run loyalty clubs, like $100 off every 5th booking. They also will tend to run weekly schedules instead of a couple days out which makes planning easier.
Another big difference is there is a lot more price stratification within Toronto agencies, a "bronze" level escort might be $260/hr while a "platinum" level escort at the same agency might be $420/hr. Compare to Montreal, where only a handful of agency girls get significantly higher rates than their agency counterparts.
I’d give Toronto serious consideration if your primary interest is in seeing SPs as a traveler, not taking into account any other considerations.
You can check out the Terb board for more information too.