OP, if you're looking for the best gains, best sound, and best customer service then FI is the company/exhaust to go with. the product is above and beyond in quality. the HP gains with a TP or HFC plus CBE is well worth the cost when you add in the amazing sound factor.
like others have said, try to not hesitate if this is the route for you. there is about a 10-12 week wait time due to extreme interest in the systems and that they are all hand made. the wait time should speak for how desirable this exhaust is for the 370Z.
I have videos on my channel of the non-res TP and non-res CF CBE. also I have videos of my FI straight pipe system as well.
https://www.youtube.com/user/fpenvy