Looks like I'm the lone voice of dissent on the 9K screamer. S'ok...one riot, one ranger.
Don't get me wrong, I'm ok with a 9K redline, I just don't like the sacrifices that come with it. Consider two other high-revving Japanese offerings from the same generation as the 350Z: the S2000 and the RX8 - in the stock form they're gutless.
The S2000 - everyone spouts the 237 bhp @ 8,300 rpm from a 2 litre engine but what about
153 lb·ft @ 7,500 rpm - that's stock 240SX torque territory there.

Mazda's rotary fares a little better with the torque coming on a little sooner...177kW (237 hp) at 8200 rpm and 211Nm (156 lb-ft) of torque at 5500 rpm, but loses a little horsepower.
I'm not opposed to either of those cars, when properly tuned & modified, or to the idea of high-revving engine...just not in my Z. With the now proven demand for rear wheel drive cars I can finally see a future where Nissan could develop and market a spiritual successor to the S-Chassis (S13, not S30!) and I think that's where a smaller, forced-induction engine belongs...you know, like the original
Japanese S13/14/15 cars.
The potential problem is with cannibalizing sales from the Z. Porsche had to deal with this with the 911 when they made the performance of the Cayman-S so potent.