If there is one region in Canada where you can see the contrast, it's Ottawa-Gatineau: Québec, where winter tires are mandatory and Ontario, where they are not. Drivers go from one province to another on a daily basis. You can easily spot an Ontario vehicle without winter tires, especially in a storm. Unless I move to Southern Ontario (or Florida!), as a Quebec driver, I would never, ever go without winter tires. Once you know how better they handle, you don't want to go back. Of course, you have to adapt to driving conditions!
One last point, many Ottawa drivers do use winter tires too!