Yep...I love the sound and the pop when changing gears fast, but hate the flat spot (however, you'll learn to live with it) and the lack of performance gain.
TBH - best setup was: Miltek 200 cell sport cat & Miltek catback.
Don't know, maybe it's the remap...
Please, compare the diameters & runners with the OEM manifolds because I was looking on the ebay and they claim more than 7bhp and I believe that you know/realize what that gain means to our cars.
If this was true, I would buy the manifold this instance.