Stori, I have replaced my dampers with yellow adjustable Koni's at 170000 km (about 110000 miles). My 156 is not lowered (apart from the Sports Pack the car came with). The handling now is a bit better and, since I have adjusted the stiffness, I don't have any problems touching the road anymore.
I also think the original dampers are too soft. The 147 was basically build on the same platform, though a bit shorter, as the 156, so it appears to me the effects should be alike
Robert AR156C #94