This weekend our F20 was allowed to play with some other cars on a 3 km track on a frozen lake. With studless tires, it was sliding around happily, lap after lap. I was driving very sideways at times, but the car is easy to control, so I got no spin outs, and didn't touch any snowbank. The fake differential brake works very well, and the balance of the car is perfect. I am also very pleased with the steering.
Most of the driving was done in DSC Off mode, which unfortunately forces comfort engine mapping. Very annoying.