the JTS springs work weli, its just too soft. My old coupe always had resonably soft leaves (my own setup) to help get power down and a swaybar to control roll. I think a swaybar upgrade on my current Datto will make it really good. I have one for it and it would be on by now if i didn't think it was a bit too big.
JTS setup:

what I want it to handle like :
