I've read this thread with interest, and am surprised how strong feelings run on this issue! My zetec car was running the original bilsteins which were certainly tired. I wanted to replace them, and following the chorus of advice on blatchat to speak to Simon at meteor, did just that. I decided on the core single adjustable dampers supplied by Simon to his recommended spec for road use. They were fitted by the team at pgm who also set it up on their flat floor. I am not qualified to breakdown where the improvements have come from, but whilst I would say the car may be marginally firmer, it is significantly more comfortable on the bumpy roads in France and uk that I enjoy most in my car. The confidence improvement is huge, and the speed that can be carried where before I would have had to lift off was very noticeable to me and to those in our little convoy to sarthe. I am sure the magic worked by pgm is a big part of it, and maybe the original dampers were shot and new billlies would have done the trick, but I certainly haven't ruined the ride and am enjoying the car more than ever before. It wasn't cheap, but I am very happy, and can now stiffen things up on track and that will be a whole new world of experimentation and fun. I hope that's useful, but of course caterham get very good results with the std dampers, so if people prefer that, good on them!