I have the KW Clubsport 3-ways and love them. I used to have Eibach springs on the EDC dampers. I have not felt a significant compromise on the street and in fact like the ride of the KW's better. I have not yet had them on the track so I can't speak to their performance in that environment. Send me a PM if you would like to sample the clubsports.
'13 M3 - Silverstone II - Sold
'04 M3 - Jet Black - BBS E88, KW Clubsports