Straight line with equal drivers, 350z is slightly faster than the s2, but the s2 is a bit ahead of the g35 from my experiences.

On the circuit the s2 is more capable. The 350z isn't bad, but I heard people say if you drive it at 10/10ths, it doesn't just feel right. You have to take it a step below, whereas the s2 is great even though the 00-01's are a little tailhappy while the 04s+ are more balanced probably because of the wider oem rear tires.