I personally believe it depends on the vehicle as well. I am a winter tire believer and buy it for all my cars. But my cars have always need them; Camaro, RX-8, Cobalt SS, WRX (summers stock on the rims). However my parents Minivans and now Rondo do just fine on a good set of all seasons. I would still put winters on them if they were my car, but I can see why they don't.
For safety and piece of mind, we take the stock Bridgestone 205/50R17's off the SX4 and put on some 195/65R15 Winter's. Turns the car into a winter beast.
ktm - I think you'll be fine for what little driving you do. Here in Southern Ontario, we rarely get snow, and when we do it is usually plowed as well. Trouble is, it keeps warming up, melting, then freezes again and repeat. No deep freeze. Plus we get a lot of freezing rain which plays a bit of havoc on our roads too.