If you tune it so you can feel the secondaries open, you have put too light a spring in it. If you can feel the transition, the car will be slower than if it has a smooth transition into the secondary side.
I used to work with an engineer that used to work for Holley. He took me aside one day at work and gave me some "tips" on how to make them run better. The secondary spring was one of his recommendations. He didn't tell me what color to run, but told me how to tune it in.
He also said that the Annular Discharge Boosters were very good.
