It will depend on how much snow you get where you live. I live in the snowbelt east of Cleveland Oh. and this will be my second winter with the xb. I drive mostly city where the roads are plowed so I don't have much trouble, however, when I have had the opportunity to drive through deeper snow it can be an eye opening experience! With the wet/heavy snow, I had trouble getting the xB to move from the parking lot with about 4 inches of snow. I finally turned off the traction control and was able to rock the car to get it going.
I think stopping is more of a challenge with the stock tires, seems like the ABS is always kicking in, more than my van did.
If I traveled on snowy roads more I would get snow tires, I think that would help a lot.
We've had a few inches of snow in the Chicagoland area over the past couple weeks and I have been very impressed with the xB so far. Definitely turn off the VSC in deeper snow, or it will want to sit still. Every time I get a new vehicle I like to go out and test the limits in a vacant parking lot after the first snow. It allows you to get a feel for how it can turn/slide, stop, and accelerate.
The xB weighs enough that it gets great traction with the stock all seasons and holds very well on the icy roads. I was in an area where several cars had slide off the road and I felt very confident. As with any car and winter driving conditions you will need to accelerate a little slower and give yourself more stopping distance, but the xB seems to do very well in the snow and ice