My Konis are yellow and the full firmness is 3. There is a marked difference. My car would do a very slight (VERY, VERY slight) nose diving during hard braking when it was set to soft. It was so slight that it wouldn't cause any problems but I wanted a real firm ride and the firmest setting is just what I wanted. Little swaying on turns, little diving on hard braking, and no crouching in the back during hard acceleration.
I haven't gotten my wheels aligned yet because I wanted to allow a full two weeks to allow the springs to settle to their final position. The wheel does not pull to any sides however because the shop I went to did a wonderful job, It steers great, but will get an allignment Friday or Monday.