I run Nokian Hakkapeliitta RSi tires on my Accord at home (in Regina) and find they make a world of difference. Bear in mind that all-season tires lose grip once the temperature drops below about 10 C. At temperatures as warm as 7, winter tires have better dry road traction than all-seasons do and the difference increases as the temperatures fall.

The hard rubber of all-seasons is generally designed for long life but the cost is impaired cold-weather traction.

Bear in mind that running winter tires means you can wear your all-seasons down more than you would dare if they need to see snow. I got an extra 20K km on my last set of all-seasons because, while they were miserable on roads with even a skiff of snow, they were still fine even in fairly heavy rain. I basically drove them down to the wear bars (when the tire manufacturer suggests you replace them). You would have to replace them much sooner if you intended to use such tires in the winter.

The big advantage of winter tires to me isn't so much their starting and stopping traction (although it's much better than all-seasons give you), it's the side-to-side traction. You have to work a lot harder to make the rear of your car skid if you have winter tires, and you can get control back a lot more quickly.

I rarely rent in the winter months in cold climate areas (I tend to travel to warm places in the winter or else have someone else transporting me) but I would absolutely prefer a winter-tire-equipped rental car if I could get one and winter tires were appropriate for the climate at the time of year.