When it's cold and icy I use my MTB with unstudded tires but i drop the tire pressure a lot. that gives me excellent grip. Here in town there's a road that gradually climbs from the river then gets steep at a bend as it continues upwards. Sometimes that road gets so icy that cars can't make it up and slide down the hill again. i can be like a pinball machine. weith the MTB tires at very low pressure I can ride up (or down) that same road with no problems and even brake without sliding out of control.

cheers