I have already driven the Nismo, but no GT yet.
The Nismo suspension was stiff, but it wasn't so much of a problem. The real issue for me was with the damping (or lack of?).
The car was bouncing a couple of times over its spring each time I was driving over a bump, especially with this level of stiffness. If felt under damped if I'm correct.
Now that wouldn't be so much of a problem with a soft sprung barge, but with firm springs I found this uncomfortable.
I'm sure others will disagree with me, and fair enough I'm no specialist.
Over than that I loved the car. If I could tune the suspension, I would probably consider one over the GT just for the sound it makes.
always worth checking on any nismo you view... they often do not remove the transit spacers which are fitted in the front coil springs, most customers have taken delivery with these still fitted ! a slight oversight on the pdi