I've just moved over from an S2000 to 350z and desirabilty are comparable but how they both deliver power are completely different and you really do have to adjust your driving style from one to the other.
S2000 feels very lethargic prior to VTEC but when you hit it, it just signs! Whereas the 350z has plenty of low end grunt and you can end up being lazy with the gears!
CTR's iVTEC I find a bit better to live with on a day to day basis (I used to have one prior to S2K) as there is more useable low end torque.
I think my preference is I need something more easier to live with on a day to day basis. Whilst I dont use it for work the 350z fit the bill for me