which is the best

 

I have the Dr. D race system in my 450...i love it...it is the most pipe for the best price..you can buy these 700 dollar pipes, but for the price and what you get Dr. D is the best pipe out there...

 

Dr D or the WB carbon pro II. The D is less expensive, but the WB looks better. I run the carbon pro, and it has extremely good low, mid power. Had the PC titanium-4 before. It was more of a topend pipe. I definately gained a lot more usable low-mid power when I switched to the WB.
I just pay attention to what 2 wheeled MX'rs are doing, then go from there. Both the Dr D and the WB carbon Pro II gets used A LOT! There is a good reason too, the power is awesome!