Just got the GT Spec chassis braces installed today on my 2012 Nismo.
Front
Rear
I was skeptical about being able to feel any difference but I must admit, they do make quite a difference. I cannot say whether or not they make the car "faster", but believe it or not they actually make the ride in my Nismo quite a bit smoother! I was not expecting that.
The car feels MUCH more solid and does not rattle over bumps anymore. I always assumed that the ride was so rough due to the stiff suspension of the Nismo, but now the car soaks up bumps much better. Very nice surprise.
Turn-in is quicker with more precise steering feel and there is less understeer. The car felt more neutral through a couple high-speed sweepers (on ramps) and definitely felt more "planted".
Also, I do not seem to be spinning the rear tires as much, although I only did a couple WOT runs so this may just be a coincidence.
Overall, I am very pleased. Is it a MUST have? Probably not. But if you want to liven up the handling and smooth out the ride of your 370Z, I would recommend it.
Purchased and installed at Jotech Motorsports in Garland, TX.