Nismo springs vs. Swift

[Nism0370]

Has anyone compared lap times between the stock Nismo suspension and the Swift springs on Nismo shocks around a track? I have the swift springs on nismo shocks setup. During my last DE event, my instructor was surprised that I would want to change the handling characteristics of a car with countless hours of research and development. His point was that stiffer is not always better and that you should have a certain minimum amount of body roll for proper weight transfer around a track which has been researched by the nismo engineers with a huge budget. Another instructor (thinking that I had coilovers) asked if he could soften the rear shocks to improve handling. I know that coilovers are best (adjustable, ride height, etc) but I don't want to spend that kind of money at this time. I don't know if I should keep the setup as is or swap spring back to Nismo oem for the upcoming track season... Any help would be much appreciated! Thanks--