I have a 370Z. It is badass. A number of us here have one, actually. Mine is a bit modded, but it gets compliments every single time I drive it. It's fairly light, well balanced, the torque band is nice and flat, torque comes in fairly early for a high-revving V6 too, there are tons of aftermarket options on the car (a tune reeeallly wakes it up), the high-end power is very welcoming. It's extremely fun as hell to drive, even in automatic (mine is a 6MT though).
A spec'd interior is a pleasure to be in with nice materials that a C6 Corvette, Evo, or any other car that's been suggested cannot compare to. The interiors of the 370Z and G37 are very very similar, but the 370Z ditches the polished faux aluminum trim and the analog clock (the screen, navi, and all software is identical otherwise).
I averaged 28MPG on a 1100 mile drive to my new home in Florida - with over 120lbs of stuff in the rear. And contrary what someone said, no a Corvette does not get better fuel efficiency than a Z. The ratings are 17/21 for a 6MT Vette. And 18/26 for a 6MT 370Z. A considerable difference on the highway. I don't even think the two cars should be compared - they have way too many differences, they're not direct competitors.
But I've said it before and I'll say it again: as far as sports cars, for the price, the 370Z offers a bit of everything someone would want, without any excess. It's the all-arounder capable of performing multiple tasks with room from the factor to excel with just a few upgrades.
Though I will say that with the OEM BBK and Nismo pads, the braking is sensational - I recall seeing a test that ranged from 99-100ft with the optional pads. That's supercar stuff, quite frankly. But the pads are pricey and they dust to no end (my car has them), and they are meant for track duty to avoid fade (see Motor Trend's 370Z Nismo crash).
As many others have in the past...feel free to PM me if you decide on a Z. I've helped probably 5 other GAFers from around the world find the right Z for them via PMs.
