Tire technology has really changed over the past few years. Winter tires are proven to improve driving, braking and handling over conventional tires. Yes, you could get by using conventional tires in the winter but traction and braking will be severely compromised. New chemicals used to remove ice and snow make the roads very slippery at times.
Transport Canada recommends the use of four winter tires, not two. Insurance companies are rewarding clients with incentives for using winter tires as well. New winter tires are much quieter than earlier models because of design and once you feel the difference winter tires have over conventional tires you will be amazed. Even on bare pavement, winter tires out perform conventional tires when the temperature is below 7 degrees Celsius.
Your safety is priceless, so make the investment.