The front tires (255/35) have directional pattern in order to provide a more precise steering. They are also designed to perform better in the rain. The rear tires (285/35) have better grip. These are the stock tires on the M3 GTS. I am also planning to try them when my front tires are worn out. They don't have so much grip like Michelin Cup, but they are better in the rain. On the other hand, they are not that good in the rain in comparison with a sport tire like Michelin SuperSport or Pirelli Zero, but they have better grip when dry.
For me they seem like a good compromise if you use your car as a DD and don't have a second set of wheels for the track. Apart from that they fit perfectly on the 359m wheels and don't look so stretched like the stock wheels.