The precision and repeatability of the pattern are identical between these four versions. the only tradeoff is less travel for more shifting effort. with the 0% being closest to stock effort and the 40% requiring the most additional effort but having the least amount of travel.
Which to buy?
If money is no object get the AutoCross is the best you can have.
It is just the best kit around.
If mainly used on track either the 30 or the 20% reduction would be suited.
If used predominantly on the road the 20% for sure.
A ZHP or Clubsport knob will sit lower than the stock knob and increase the reduction a couple of percent