To experience both the normal Z and the NISMO tuned Z, is more than enough for you to quickly decide which is for you. The 2 are very similar interior wise, power wise, and that is where it ends. The nismo, is a much more aggressive/racing type car, yes you can travel, the gas mileage is comparable if you can keep your foot out of it! Good luck with that. The car handles like a dream, you can push it to the edge of your own limits and it still wants more, the stiffer chassis, and upgraded suspension make this car worth the little extra it costs to own, over a normal Z. If you like to drive, and love the road this car is for you!!! If not then I suggest a normal Z.
Body kit, suspension, wheels, although not too much is different, the interior is nice, storage is ample, a little bit of a pain, one of the larger storage areas (lockable) is directly behind the pass. seat.
Stereo! It is absolutely abysmal, the car is what it is, the stereo should at the very least match to a degree, I wouldn't put this stereo in a car worth much much less.