I have a titanium-4 procircuit full exhaust and am very pleased with it. It was way to expensive, but well worth the massive weight savings over stock, and even over aftermarket aluminum exhausts. The power gain was nothing short of incredible. I have no idea what I gained, but it was fricken nuts. If you get 2-3 horsepower by just taking the baffle out, then you probably get 8-10 horsepower with the procircuit. I am extremely impressed with it, and have nothing but good things to say about it. ITS SOOOO LITE!! And, another positive thing, being that its titanium, you dont have to worry about polishing it up, and the titanium color looks really good on the blue plastic/ grey frame 450.
The one your talking about is most likely the t-4 which is aluminum, and I am sure looks fine on the white/red. I am pretty sure that is offers the same horsepower gains as the ti-4.
Good luck! Sounds like you cant go wrong with the HMF exhaust system either, sounds like a real good unit