If you normally required a 5 kohm resistor and switch to a lower resistance rotor you may notice a slight difference in engine firing. Compare the spark produced by the 5 kohm resistor in the first trace to the traces for a 1 kohm resistor and one that has had the resistor removed (0 kohm). The 5 kohm trace has a very sharp fall from the peak voltage required to fire the spark plug, to the burn voltage level where the bulk of the current flows. This results in the longest burning spark. As the resistance of the rotor decreases, the length of time it takes to fall from peak voltage increases and the shorter the spark. Don't try to outsmart VW/Bosch: they knew what they are doing when they specified which rotor to use.