I can vouch for it, Had one on my 06 Cobalt ss and my low end was way better, Throttle responce was instant! Better mid range but top end was about the same... Although it did get to it's top end alot faster :-P
Car's gone now.. Not my doing!
Tons of parts if anyone needs anything.
SMS Big bore throttle body, Edge products 660cc injectors, SMS fuel rail, Conversion harness for the ecotec to seimens injectors, exaust manifold, cam gears, super charger, complete wire harness, coil pack's and more!
Just PM me if you need anything!