I've got the Jamex Sportline kit on my valver - the yellow ones. They're fine. Allthough I had the joy of rubbing arches on the rear near side the other day due to the rather heavy passengers in the back. Don't know it that is becuase of the fatties or my shocks not being stiff enough. Hey ho.
I can only compare these against the shagged OEM ones that I took off the car, so I'm not fountain of knowledge on lowering kits, but I guess my car rattles becuase it's old and not necessarily due to the lowering kit and rough road :-P