^^
I agree with you on the feel, fun factor etc.....RX8 owns the 350Z on those counts from every review Ive seen. As for the 370z being as fun to drive as the Cayman S or RX8 that will indeed need to answered in a comparo. Just because the 370z can hang with the Cayman S doesnt mean its on the same level of balance and feel as either the RX8 or Cayman S. Power and enough handling can help a car make up for shortcomings like added weight, less ideal weight distribution etc. Pure track numbers dont convey the fun or balance of a car.
Example ACR horribly rapped the Audi R8 on a track. But the R8 felt much better and had more enjoyable handling characteristics compared to the mighty ACR. Im thinking its gonna be hard for a front engined, 56/44 car like the 370z to mimic the telepathic reflexes of a mid engined car like the Cayman S or the superbly balanced RX8. It may tie it or beat it on track but if past reviews are any indication the Cayman S will be the more satisfying "drivers" car. Speculation can be fun but Im hoping the 370z can at least come close to not only the performance of the new Cayman S but also come close to it in the fun factor as well.