It will cost you 20% of the cost of the M2 with little to no benefit... No benefit on the street and not much better than OEM rotors with good track pads at the track. The main advantage of CCB is they handle heat better. You won't see those temps (to induce fade) on public roads. You can also deal with the heat issue with proper pads on the track. In terms of stopping distance, there is little =difference (lots of discussions on the M3 forum) unless the steel brakes are fading which, as mentioned, you can virtually eliminate with the appropriate pads.
CCB's advantage, IMO, is the ability to go street to track without doing anything, dust and a bit of weight. The downside is HUGE cost. I can't imagine $11,000 is worth not having to clean the wheels a little more frequently
