I have always found that grip remains the same but the line between neutral and snap oversteer is much finer. You are relying more on the tire when when reducing roll and this can cause them to overheat in some cases. The main advantage is that the reduction of roll at the rear makes the car transition much quicker and allows the car to "sqaure up" sooner. Again, something these progressive springs do not seem to allow. Hense the reason we are running the shocks stood up and the higher real roll centre. Keep in mind that you can go to far, which is why we need to do more testing.