Have been driving with these for almost 50000km now, been through Nordic winters, European summer heat waves etc, temperatures ranging from -20C up to over +30C, wet and dry, everything.
When they were brand new, it was difficult to fault these tires. They preformed better than the aging premium Nordic winter tires in the snow. Comfort good, dry performance as good as you could expect, wet performance was also fine.
After 50000km they all have around 5.5-6 mm left. However, the way the treads are designed meant that around the centre line, they have less than 1mm left at this stage (there is no uneven wear or under/over pressure, tracking on the car is checked yearly, no punctures/repairs) - the base of the tire has a V shape so the centre of the tire also start with less mm when they were brand new. This interesting design and wear pattern meant that there is now a significant drop in performance: aquaplaning risk increased dramatically, wet grip is completely gone, braking performance in all conditions deteriorated. Noise also increased significantly.
So even those most of the tires still have more than 5.5mm left, they need to be replaced. They have become almost dangerous under all conditions.
Perhaps they were designed this way, but I was expecting more even and consistent performance through the lifespan of the tires. Unfortunately I will not buy them again.