When I looked at various different exhausts and heard some of the ones around I didn't like how most of them sounded
So I was not sure as to which one to get and how would they improve the performance.
Eventually I heard the one I wanted on a ZX-6R at a local meet and thus the purchase began.

I bought a Blue Flame Dual Port Coloured Titanium race can, and can say I am glad (see dyno & videos).