I've tried all my bikes at one time or another (6). I found the road bikes cut through snow much better but have poor traction. I found the mountain bikes get great traction but cut through the snow poorly. I also tried studded tires on the mountain bike. I ended up using the Redline cross bike with wide tires and a snow tread and it works great. I guess you might want to try using a cross tire in the winter time and see how it works for you. By the way, the Redline is a great all duty bike. Winter, spring, summer or fall, all you have to do is call, and it's up to the task.
Later!