Simplistically, the Springs determine the amount of weight transfer and the Dampers determine the rate at which the weight is transferred.
GT3 is relatively insensitve to Spring Rate changes but very sensitive to Damper changes - I've often found that altering Bound or Rebound by one click can have a marked impact on lap times.
As to whether 1 is Full Soft or Full Stiff for Dampers is a question in some debate. I can't give you a definite answer on that one as I've experienced evidentiary handling on different cars that give conflicting responses. Trying both low and high Damper settings and seeing which suit you best is probably your most productive option.