I'm riding on a different brand of coils altogether (Eibach Multi-Pro R1s) and the ride quality was absolutely *amazing* for the first few months, and has since deteriorated to the point that I'll be sending them back for a rebuild. They really don't like the cold, and I'm talking extreme cold, ie. -32*C which is the same as -32*F. Hasn't gotten there quite yet, but it'll only be getting worse. Coilovers are unfortunately not for the winter and I'm now questioning whether I should just go to a Koni Yellow/good spring combo. From this thread, I've basically decided to stay away from KWs, unless to go the less expensive route and buy the V1s just to tune in a perfect height.. Bilstein PSS10s, I'd like to try though.
Good luck whichever way you choose! E9Xs look so good dropped
Also, I'm sorry if it seems like I'm not contributing, but the KW subject always comes up and with so many people running them, I've thought about trying them out so many times. What attracts me to them (JUST AS THE EIBACHS DID) is that they're a stainless steel or aluminium damper (I forgot, but they're not supposed to rust) and I was hoping I'd get away with running them through the winter at a reasonable height. Alas, not possible it's looking.