Studded's pretty silly around here for the most part. It gives you traction on ice, but how often do you ride on ice?

Usually it's snow, slush, or just dry pavement. Slicks are best when it's dry out, and something with tread are best the rest of the time. In 700c that'll be CX tires.

Oh, and 18mm is really silly. If you want something for bad weather, start at 25mm and go up.