Final exhaust opinions before I pull the trigger

RSZED

With Greddy or GTHaus you won't make the same amount of power you will with amuse or the E370z (specially in the sound Dept Loudness+power+unique sound= better exhaust.) trust me ive had different exhaust for G35 to 37's and Greddy as far as quality is good but the power gains are very low. GTHaus is more for sound but their exhaust won't deliver as far as quality nor dyno numbers either. The fellas back at NAGTROC GTR forum have had complained about GThaus having welding issues specially with their titanium products, and as far as i'm concerned, if they can't make quality products for a GTR or an M5 what will you expect with the 370z??