I think both options will suit your needs. When it all comes down to it, the only way you can truly say which one you like best, is to drive em' both.
Well since that will prolly not happen you are $hit outa luck
Just joking,
Comes down to personal likes and dislikes and of course "MONEY". I would like to say that supercharger gives more liner power than turbo but it is not that way in the case of the VQ37 and Garrett. Both TT and SC are liner through-out the power band so no instant surge of power for the GTM TT kit. Toyota Supra's are well known for massive spikes in power, which some say is uncontrolable. This will not be a problem with either kit.
Many say turbo is not as reliable as supercharger but I think it can be just as reliable as a supercharger, if installed and tuned right, and maintained right. In a turbo setup there are more parts and most important; more moving parts, soo....using a little
statisical math will tell you there is a overall higher chance of failure. So if the install was done flawlessly, its the parts you got to worry about doing there job at this point and the GTM TT kit uses high quality parts. And there are many sensors and gauges you can buy to monitor these parts to make sure they are doing there job.
Supercharger is sure alot cheaper though. Like a said in the other post, after all is said and done a slick set of twins in the 370z will always hold the crown in my book.
-The End-