For some remanufactured aftermarket clutches, spring problems may be related to the fact that they are remanufactured.
I drove an NSX with an Exedy clutch and it is actually pretty good for the track. It teaches you to shift quick like you should. It's really strange having an engagement range that feels like a few millimeters. You're letting out the clutch real slow to feel for the engagement point, and then bang, it's suddenly fully engaged and you either launch the car or it stalls. I learnt to rev the engine higher and remind myself that the engagement point is much higher than on my car.