I've been running one of these pipes for over 15 years and love it. I started off small but when I went to a fully modified 62T motor, this pipe really woke up. The mid range and top end of this pipe is awesome. When I switched from the stock 38's to 46 mm Novi carbs, I got a lot more bottom end. This pipe really needs a motor setup that breaths.
The only issues I've had with this pipe is that it leaks a lot between the exhaust manifold and the chamber. You really have to dry fit it and line it up good before you put the coupler and O-rings on but it will still need replacement O-rings after each season.