^^ i'm not gonna say i doubt it, but i am gonna say it's unproven. user bias makes you 'feel' a whole lotta things. put it on a dyno and show me
2.5" exhaust is better than the stock exhaust for 'enthusiast driving' anyway. i'm not sayin your exhaust is bad or anything close to it, but i don't jump on anyones bandwagon without proof or a great reputation for putting out proven products previously).
good luck with everything though, chris